From the twin planets named Krypton came two lasses who would become Girls of Steel, and fitting female facsimiles of their cousins... the Supermen. Of course, we know these gals as Kara, or as they are more famously known, as Earth-One's Supergirl and Earth-Two's Power Girl.
Indeed they were not alone in carrying the name of a male relative, for the original template for this time-tested model was that of Mary Marvel. The twin sister of Billy Batson, Mary Boomfield was raised by another family when her own parents died early in her life, much as her counterparts as all three were orphans. Learning that she too possessed the same abilities as Billy, she joined Captain Marvel in his crusade for justice. Like Supergirl and unlike Power Girl, she was proud to adopt a similar costume and identity. And like Power Girl and unlike Supergirl, she was a member of a team, her world's premier one...the Marvel Family. Also like Earth-Two's Maid of Might, Mary was kept youthful in suspended animation for decades until the mid-70's when she debutted... as had Power Girl. Yet it was Supergirl whom she would meet, when both gals saved the guys from a destructive confrontation with two Earths at stake!