Earth 489: Supergirl Legacy Redux
Supergirl I - Kara Zor-El/Karen Starr: Kal-El's older paternal cousin, Kara was intended to arrive on Earth at the same time as Kal, but she was stranded in the Phantom Zone after Krypton's explosion knocked her rocket off course. Masquerading as Kal's cousin who was orphaned in a house fire - not entirely far from the truth, if one thinks about it - Kara would soon become the first Supergirl, and would later form the Titans alongside Dick Grayson, Wally West, Garth of Atlantis, Donna Troy, and Roy Harper. However, it didn't take long for Kara to want to distance herself from her now incredibly famous cousin. Altering her costume, removing her house symbol from the chest, and changing her name to Power Girl, Kara reinvented herself entirely. This extended towards her civilian identity, as "Karen Starr" would later found StarrWare Industries, a technological firm dedicated to saving the environment. Karen's attempts to reinvent herself have taken her to many strange places, including the 30th century, where she was a member of the Legion of Superheroes, and the not too distant past, where she and fellow time lost adventurer Huntress - not the same as the current, although Karen has stated that her name is also Helena - were members of the Justice Society.
Supergirl II - Cir-El/Mia Kent: The woman who would become Mia Kent was an unfortunate victim of a disease which rendered her brain dead. Noting her resemblance to Clark Kent and Lois Lane, the Brainiac of this time period kidnapped her and altered her DNA to include both their samples and to gift her Kryptonian abilities. Sending her back in time with false memories of being the daughter of Superman and his wife, Mia was intended to usher in a new era where Brainiac ruled supreme. But it didn't take long for Mia discovered the truth. The artificial Kryptonian sacrificed herself to prevent this terrible future from coming to be, taking Brainiac with her. This would be the last anyone would see of her, or this time period, until the time travelling Rip Hunter would discover her stranded in the time stream and return her to this timeline, where she is once again Supergirl.
Supergirl III - Kara In-Ze/Linda Lee Danvers: The half Daxamite cousin of Kara Zor-El via her mother - unrelated to Kal-El, mind you - Kara In-Ze was living on Daxam with her parents when Krypton exploded, knocking its neighboring planet out of orbit. In order to give her daughter a chance to live, Kara's mother used what remaining resources she could to build a rocket to send Kara out into space, at the cost of her life. This attempt ultimately paid off, and soon Kara found herself on Earth, where she would reunite with her now older cousin (funny how history seems to repeat). Operating as the next Supergirl, Kara would be adopted by the Danvers family, scientists Jeremiah and Eliza as her parents, DEO agent Alex as her older sister, and a baby brother named Wally. However, Kara's anger with what happened to her home planet and her biological parents flared, and she often clashed with her new family, as well as her teammates on the Titans and the second iteration of the Young Justice group. She soon found purpose, however, when she took on the mantle of Flamebird - one she shares with Bette Kane and Thara Ak-Var - and became partner to Stephanie Brown, when she took the name of Nightwing, and later Jason Tood when he did the same.
Supergirl IV - Keira Zor-El/Claire Starr: As mentioned earlier, history has a habit of repeating, and Claire's story in no exception. A clone created from the combined DNA of Kara Zor-El and Lena Luthor, "Claire Clarkson" was created by Ultraman to bolster the ranks of the Crime Syndicate, a villainous counterpart to the Justice League. Adopting the name of Ultragirl, it didn't take long for Claire to discover her true origins, or realize that what she and her "friends" were doing was wrong. Claire turned against the Crime Syndicate and, after confronting her creator and adoptive father, discovered her genetic origins. She in turn revealed this to Power Girl, who would take her in as an adoptive daughter, feeling responsible for her. Claire later joined the world of heroes as the fourth Supergirl, but never felt worthy of the name, and once Cir-El was refound, it didn't take long for her to abandon the name and assume the alternative of "Snowbird".