Supergirl is a fictional superhero that appears in American comic books published by DC Comics. Supergirl was created to be a female counterpart to DC's popular hero Superman. Her real name is Kara Zor-El
Kara Zor-El (originally, just Kara; Kryptonians during the Golden Era used a single name for most women, and a two-syllable name for men; thus the addition of the patronymic to the female name is a contemporary convention) is the last survivor of Argo City, which had survived the explosion of the planet Krypton and drifted through space. The city had been covered by a plastic dome for weather moderation, devised by Zor-El, the younger brother of Superman's father Jor-El, a climatologist and engineer. The dome held together a large chunk of land mass under the city as it drifted through space in the general direction of our solar system. However, the bottom-most layers of bedrock were affected by the explosion of the great planet's fissionable core and underwent a slow but steady chain-reaction, turning into green Kryptonite. Using raw deposits and refined materials at hand, the residents of Argo City laid down a ground shield of lead foil to protect them from the developing Kryptonite. Zor-El was also able to fashion a makeshift propulsion system to try to accelerate the city's approach to the Solar System. During the roughly thirty years Argo City traveled through space, Zor-El met and married Alura, daughter of In-Ze, who in turn bore their daughter, Kara—blond like her parents. But before the propulsion system was able to steer the city toward Earth, a deranged citizen named Jer-Em, who was suffering from survival guilt, damaged the exhaust, veering Argo toward a swarm of meteors that crashed into the underside of the land mass on which it rested. As the inhabitants of the colony were being slain by the green Kryptonite radiation released by meteorites shredding the lead barrier, the adolescent Kara was sent to Earth by her father Zor-El in a rocket, to be raised by her cousin Kal-El (Superman). Fearing that she might not be recognized by Superman, Kara's parents provided her with a uniform which was closely based on the one Kal was wearing as the Man of Steel.
Super Best Friends Forever (DC Nation Shorts) EditThis verison of Kara Zor-El is the feisty, hot-headed, impulsive and snarky Superman's cousin from Krypton. She lives in the Kent Farm and often teams up with her best friends, Batgirl and Wonder Girl to fight crime, take down super-villains like Poison Ivy, Cheetah or Solomon Grundy, and pull pranks on Lex Luthor
Super Best Friends Forever #3: Grounded Edit
While after Supergirl grounded for no reason, Superman smash Supergirl with a tractor, until she more muscular when she lifted the tractor and throw it back on him.