Kara Zor-El the cousin of Superman first appeared in Action Comics #252 (May 1959) and was the first of several people to use the name Supergirl. She was killed during the Crisis on Infinite Earths in 1986. Kara was reintroduced in 2004 in the Superman/Batman comic book series.
Kara Zor-El was the last survivor of Argo City of the planet Krypton, which had survived the explosion of the planet and had drifted through space. When the soil of the colony was turned into Kryptonite, lead sheeting was placed on the ground. But meteorites pierced the sheeting and the Kryptonians began to die of radiation poisoning.
Kara was sent to Earth by her parents Zor-El and Allura to be raised by her cousin Kal-El, known as Superman. So Superman would know Kara was his cousin, her parents provided a costume based closely on the Man of Steel's.[1]Upon meeting Kara (who had begun to display powers similar to those of Kal-El), Superman decided she would become his secret weapon, and explained that her presence on Earth must be kept confidential while he trained Kara in the use of her new powers.
Kara adopted the identity of Linda Lee, an orphan at Midvale Orphanage, hiding her blonde locks beneath a brunette wig. During this period and for two full years, Linda interacted with humans mainly on a person-to-person basis performing good super-deeds on a save-the-world one at a time ratio, using clever schemes while trying to avoid becoming adopted before her time came. A distant precursor for her worldwide - even galaxy-wide - fame that was to come soon. Travel to other times or worlds came easy, since it permitted her to be openly seen then.
Kara claims to be the daughter of Superman's uncle Zor-El and his wife Alura. The post-Crisis Kara is actually older than Kal-El; she was a teenager when he was a baby. When Krypton exploded, she was sent in a rocket (in suspended animation) to find and look after Superman. However, her rocket got caught in a huge chunk of the planet and she arrived on Earth years after her cousin did. Meanwhile, she was put in suspended animation, so while chronologically born before Kal-El, she is still the age of a teenager. Her arrival is discovered by Batman, who initially doubted that she was really Kryptonian, thinking that it was too much of a coincidence. Eventually Kara is discovered by her cousin Superman and combat trained by Wonder Woman and Artemis. She is captured by Darkseid, and after being brainwashed, attacked her own cousin. Superman defeats her and returns her to Earth, where he fakes her death so Darkseid will not come looking for her. She then assumes the role of Supergirl. But she feels out of place, not sure where she really belongs.






