Origin
Kara Ken is sister of Superman XX, Klar Ken, in the 30th Century, the two are direct descendants of Kal El, the Original Superman.
History
Kara lives waiting for the day turns 21 years, to wear Supergirl’s costume, her family-right mantle. Age is a Family Rules, which it obeys even with the death of its parents. Her overprotective brother, Klar Ken, who is older, if I knew she’s already done her custom, I wouldn’t approve.
Kara thinks she doesn’t need to continue attending college as she has super speed and total recall. Her brother’s overprotection annoys her, not least because it’s gotten worse since her parents’ deaths.
Millions of robot soldiers attack several planets, including Earth, after Superman (Klar Ken) starts his career.
Kara finds out from Lena Luthor that the leader of the robot soldiers is Muto. Kara disobeys the rule about her costume and dresses it. Kara and Lena Luthor decide to go to their brother’s invisible satellite, nicknamed the Fortress of Solitude, where there is a meeting with several heroes. There they are discussing the best way to stop the robot army. Kara tells Lena not to show up.
Kara, using information from Lena, warns those present that Muto has mastered the Andromeda System. Using the signature of the green lantern, Muto teleports into the Fortress of Solitude satellite and with his psychic powers disables everyone’s movements. Muto would play with the heroes before something more deadly, however, Lena causes a distraction and the super heroes manage to nullify the psychocontrol.
Supergirl and the other heroes go after the army of robot soldiers, after finishing the matter, they all decide to found the Justice Alliance to defend the galaxy.
Creation
Kara Ken was created by Dan Jurgens and Paul Ryan in Superman (Volume 2) #136.