>>92507000Lesse, to the best of my recollection there's been;
Classic Silver Age Kara that died during COIE.
POst Crisis there was Matrix who was a protoplasmic entity from a parallel dimension that was modeled after Lana Lang and could imitate Superman's powers while having a few unique ones like psychic powers and shape-shifting. She eventually merged with Linda Danvers and became an "Earthbound Angel" and gained flaming wings and fire powers.
At some point the two of them split apart again and Linda retained a portion of Matrix's powers and started acting as Supergirl in the white t-shirt inspired by the animated version. She's the one who married a Pre-Crisis Superman and had a daughter, Arella Kent, who survived the Crisis and is still tooling around in the 853rd Century somewhere. Linda eventually just said fuck it and retired, never to be seen again. Unless you count Peter David's "Dark Angel" series.
Some time around the late 90s we got Cir-El, who wore a black costume and a blue cape and claimed to be from the future and was either Superman's daughter or one of his descendants. I think she turned out to actually be some homeless girl Brainiac abducted and genetically altered in order to fuck with Superman. I don't know what became of her.
Then there's Powergirl, post crisis she had various conflicting origins including being Superman's cousin, the descendant of Arion the ancient Atlantean Sorcerer, and briefly that she was actually Laurel Gand, a Daxamite from the 31st Century who was part of the Legion. Following Infinite Crisis, she was revealed to be the Earth 2 Supergirl who somehow survived the original COIE.
Then Dan Didio wanted to get back to basics and we got Kara Zor-El, Clark's cousin from Krypton, who was kind of a bitch and this version lasted until the Nu52.
Now I don't know where we are.