- "The House of El has a lot of family secrets that nobody ever discussed. As humans would say, we were... dysfunctional." - Kara Kent, Kara
Kara Kent is Clark Kent's elder Kryptonian cousin. She is the daughter of Zor-El, the brother of Jor-El. Raised on Krypton, she made her first visit to Earth by following Lara-El on a journey to investigate a possible home for Kal-El.
Jor-El's voice at the Fortress of Solitude warns Clark that Kara may be more dangerous than she seems. Clark is also told by the Martian Manhunter that Kara's family is dangerous. Kara protests, though, saying that she isn't as dangerous as Clark has been told. The mysterious family tension in the House of El was initially a source of conflict between Clark and Kara.
- "We're not defined by our parents, Kara. One of the most important things that my adoptive parents taught me is that we shape our own destiny." - Clark Kent to Kara Kent, Lara.
Kara first met Clark after she knocked out Lois Lane (who took some pictures of her ship), warning Clark to stay away. Later, Clark found Kara looking for a child named Kal-El and once he revealed his powers to her, she realized that he was in fact Kal-El, but was confused because she thought Kal-El was a child, not an adult. Kara said to him, "You can't be Kal-El. He's a sweet chubby baby who laughed when you tickled his feet".
After she learned that she was in suspended animation for eighteen years and was released by the accident at Reeves Dam, she began to trust Clark and learned the fate of their home planet Krypton. Kara was unaware that a civil war had destroyed the planet. She simply recalled that she had been sent to Earth, that Zor-El told her that "Krypton's salvation lies on Earth" and that she and Kal-El were the keys.
When Chloe told Clark that AM and FM radio frequencies were down in Granville, Kara realized that her ship's alarm was likely the cause of the disturbance. Since there wasn't enough time to search visually, Clark took Kara on top of the Daily Planet and coached her into discovering her super hearing ability.
After moving in at the Kent Farm, Kara taught Clark about her mission to protect him and explained to some background concerning Clark's own family. He learned that Jor-El was a good, honest man, not a power-hungry tyrant like he once believed.
Clark taught Kara how to blend in on Earth, especially how to control her powers. Initially, Clark wanted Kara to "lay low" at the farm, but he lightened up when Kara saved him from some meteor-infected pageant contestants. They disagreed about Kara's independence and frequent use of her powers in public, especially flying, until Kara had an encounter with Agent Carter and realized that there are some people bent on stopping Kryptonians from using their powers. After the incident, Kara started to follow Clark's advice more closely.
Clark has shown a great deal of concern for protecting Kara's secret, even keeping her real background from Lionel Luthor, however Lionel found out that Kara was indeed a Kryptonian, when he rescued her and Clark from Agent Carter in Washington D.C.. He also asked Chloe Sullivan to create an Earthly history for Kara. Despite having made progress and becoming more trusting in their relationship, Clark didn't tell Kara that he had located her crystal.
When Clark released his mother and his uncle in the fortress, Zor-El managed to gain Kara's trust, leading Clark to believe that she betrayed him but after she realized Zor-El was going to destroy life on Earth, it started a fight between father and daughter. Clark managed to destroy the crystal but after the battle with Zor-El, Kara disappeared and Clark was frozen in a giant crystal by Jor-El for his defiance.
Overall, the relationship between Clark and Kara has become much more like a brother-sister relationship, based in trust but with usual bickering and arguing.
After a month-long absence, Kara was located in Detroit by Lex Luthor and Lois Lane. She was eventually taken back to Smallville and returned to life with Clark, but seemed to be more distant from him. In conversation with Lex, Kara admitted she felt Clark was hiding something. Lex adds to this by telling her that Clark and he were friends, something Clark hasn't as of yet mentioned to Kara. Chloe and Lana took Kara to the Fortress of Solitude where Jor-El restored Kara's powers and memories so she could help save Clark. The two seemed to have gone back to their original pre-amnesiac relationship before she was taken by Brainiac. Ever since then, Clark had been trying to find her.
- "Your path is on Earth, living amongst the humans and inspiring mankind." - Kara Kent to Clark Kent, Bloodline
Kara was trapped in the Phantom Zone, battling Zoners and fighting for her existence until Clark and Lois were transported into the Phantom Zone. After Kara initially attacked Clark, Clark recognized her and the two embraced.
After they found shelter, Kara told Clark that in his last imprisonment in the Phantom Zone, he let Zoners out of the portal who followed behind him. To avoid making a similar mistake, she remained in the Phantom Zone, even though she had access to a portal left by her father Zor-El. When Clark decided to send Lois back to earth, Kara opened the portal and she was injured by Faora in the process. Clark refused to leave Kara and tried to help free her until Chloe opened the portal, at which point Clark grabbed her and they returned to Earth. Together, Clark and Kara took the spirit of Faora out of Lois with some help from Martian Manhunter. After returning to the farm briefly, Kara decided to pursue another path. Due to rumors she heard while in the Phantom Zone, Kara chose to leave Smallville and search for Kandor, which is rumored to still be in existence. After reaffirming to Clark that his destiny is to remain on Earth to give hope to people, she flew away into space.
- "You and I are the last survivors of the House of El." - Kara to Clark, Supergirl.
After two years in space searching for any surviving members of Kandor or of the House of El, Kara was saddened to discover that she and Kal-El were the only surviving Kryptonians. Jor-El summoned her back to Earth to defend the planet from an evil Dark Force that arrived with the intention of destroying humanity.
Clark first saw Kara again during a public anti-hero rally led by Gordon Godfrey when a billboard fell towards the crowd and Kara saved them. Publicly displaying her powers concerned Clark and he quickly tracked her down. They had a brief catch-up before Kara adopted the role of mentor to her cousin by trying to teach him how to fly. Clark became frustrated by his lack of progress during his attempt at flight. Kara seemed to have a lack of faith in Clark claiming that he still had darkness in his heart and expressed concern that he could become Earth's ultimate destroyer if the darkness possessed him.
Kara made Clark realize that he was responsible for releasing the darkness when he used the Book of Rao. Feeling guilty and recognizing that Kara had greater experience with this sort of thing, they joined forces to plan to send the darkness back using Kara's bracelet. Once they tracked down the darkness to Club Desaad, Kara saw that Clark was at risk of being possessed and used her bracelet to protect her cousin.
Kara then adopted a disguise so she could continue to battle the darkness in secret. She met up with Clark and told him that she was staying. She remained protective of Clark by telling him that it was not his fight. The two cousins left things on good terms, although Kara had made Clark even more unsure of himself, but knew he had to overcome this in order to defeat the oncoming threat of the darkness.
Clark continued to secretly meet with Kara around the world.
Kara continued to help Clark to defeat the darkness by searching for the mythical Bow of Orion and was later joined by Oliver Queen. Kara wondered why Oliver was looking for the bow and if Clark knew that he was, but Oliver was reluctant to give a straight answer. Kara was then summoned back to the Fortress by Jor-El. At the fortress, Jor-El told her that she had already completed her mission and it was time for her to move on and start her own journey or continue to be in Clark’s life and disrupt his future. Considering her options, she wanted Clark to be happy and fulfill the role that Jor-El had in store for her. To that end, she chose to leave to another time. Kara tearfully watched Clark and Lois through the window of Watchtower and bid Clark an unheard goodbye before slipping on a Legion ring and traveling to the future to embark on her new destiny, thus leaving Clark for the last time.
When Clark is accidentally transported to the 31st century he learns that Kara had transported herself there using is Legion ring as she was ordered by Jor-El to do so. She arrived at a time when a war had just broken out between Earth and New Krypton. Kara arrived in the future where she was welcomed by Brainiac-5 and the Legion into becoming an honorary Legionnaire, her first mission was a diplomatic one that result after the discovery of Argo, the lost Kryptonian colony, but was sabotaged by someone from EarthGov and that event was the start of the war. Kara reveals to Clark that she allowing herself to be captured by the EarthGov regime to gather useful intel as a spy for the Kryptonians.
Kara brings Clark to New Krypton when they come across a disturbance involving Legionaires Cosmic Boy and Saturn Girl surrounded by kryptonian Eradicators. Superman and Supergirl appear on the scene defending Cosmic Boy and Saturn Girl. When Beh-Osk hears the Legionnaires call Superman as Kal-El, he realises that Superman is the last son of ancient Krypton and gets astonished by that revelation. He then calls all the Kryptonians to kneel before "Argo's salvation". Clark seems not so happy about that action and Kara says to him "Welcome home".Kara and Clark learn that this war is not about politics but actually for another more religious reason regarding the tomb of Faora. Clark and Kara make the journey towards the location of the tomb located in the heart of the Amazonian forest on Earth and are ambushed by Earth Gov soldiers ordered to prevent access to kryptonians. Clark and Kara are discussing Kara's decision to become a spy for the Kryptonians and how she doesn't like it anymore feeling she had been taken advantage of. Suddenly two of EarthGov's spaceships appear with the one shooting at Kara. Clark is ready to battle them but an enraged Kara uses her heat vision destroying one of the ships. Then they both easily take care of the rest of the soldiers with Clark using his breath to freeze them.
After that they find a huge gate with a Kryptonian symbol on it, which leads to Faora's tomb. When they enter the room they see a huge structure, resembling a palace which was built by Zod, and Kara wonders why Zod buried Faora there. Clark tells her that the original Zod and Faora couldn't have children so when his clone found out that Faora's clone, who had already killed, was actually pregnant with his child, he immediately regretted his action and fell into depression and that is why he built this palce, to honnor her. Clark also says that he made a throne for himself, to seat after he had conquered the world, in the center of the structure facing a pit where he had kept Faora's dead body frozen inside a crystalline cube. Then Kara asks again why he put the throne facing the pit and Clark assumes that that he did it because of guilt. After that Clark and Kara fly down the pit and visit Faora's body where Clark explains that the Kryptonians believe that her child was a sacred thing, because as they believe that it may have been the answer on why the Kryptonians had powers under yellow sun and not red. Kara then states that the Kryptonians won't be the first to know the answer.During the process of engaging these soldiers Clark learns that Kara doesn't share the same compassion views he has towards humanity. Kara defending the Kryptonians says that humans are not able to change and like many of her kind she does not think very highly of them and battles Clark out of frustration.
In the Comics
Kara is sent to Earth by her father Zor-El to be raised by her cousin Kal-El, known as Superman. Fearing that she might not be recognized by Superman, Kara's parents provide a costume based on the Man of Steel's own.
On Earth, She conceals her blonde hair beneath a brunette wig and functions as Supergirl only in secret, at Superman's request, until she can gain, in his opinion, sufficient control of her powers. Superman decides his cousin is ready to begin operating openly as Supergirl.
Supergirl's secret identity is a closely held secret and is known only to Superman, her foster parents, and the Legion of Super-Heroes, of which she serves as a member for a time.
In the mid-1980s, DC editorial felt that Superman should be the sole survivor of Krypton, resulting in Kara being removed from continuity. Unlike a number of other characters who are shown dying in the Crisis, no one remembers Kara dying or even ever having existed. In the early 2000s, the character was restored to current continuity in her traditional status as Superman's cousin.
- Clark: You saved me, and even though that's not the way I would have done it, I know that you need to figure out how to use your abilities your own way.
- Kara: Does that mean you're going to stop trying to tell me what to do?
- Clark: Probably not. Isn't that what family's for?
- Season Seven, Fierce.
- Kara: Take my blood.
- Clark: No!
- Kara: It'll open the portal, take you home ok.
- Clark: You are my home! You hear me, you're my family. You make me feel like I actually belong.
- Season Eight, Bloodline
- Kara: It's critical that I get my image around the city, as soon as possible. You just have to trust me Kal-El. I'm doing this for you.
- Clark: Kara, this doesn't feel as much as a favor.
- Kara: I've searched so long for my mother, and I never found her. You and I are the last survivors of the House of El. And after everything that we've been through together, I had to come back to the one place in the universe that I had family.
- Clark: Well, what you are doing right now, flies in the face of how I've chosen to live on this planet my whole life. We both know that. Now if you really care about family, tell me what you doing here and stop avoiding the question!
- Kara: I didn't want to hurt you. Jor-El has given me a mission. I'm getting my powers and image around the city as part of it.
- Clark: He gave you a mission? What did he say?
- Kara: He's let you go, Kal-El. I'm sorry. He says, you're no longer his son.
- Season Ten, Supergirl
- Jor-El: There are two paths laid before you, Kara. You can leave Earth now and allow Kal-El to embrace his destiny, or you can stay and help him, risking the future of this planet.
- Kara: Kal-El and I have fought Darkseid before.
- Jor-El: You involved Kal-El against my wishes. He was too weak then, and he was almost overcome by darkness. You have grown strong. Your will is no longer at the mercy of my command. You will need that strength to forge your own path. It is in your hands to choose.
- Kara: You want me to just walk away?
- Jor-El: Kara, your own destiny is written. It is in another place and time. But this is Kal-El's battle, and he must fight it alone. Even though a time will come when he turns away from me, in the end, he will make the right decision. He is ready. This is his time.
- Kara: He's the only family I have left. I have to at least warn him.
- Jor-El: Sometimes the greatest sacrifice a person can make is to give up what they hold most dear.
- Season Ten, Prophecy