Lena Thorul and Liandly Tyic were girls who encountered the wonders of space which literally opened their minds to new realities
Lena was the younger sister of future master criminal Lex Luthor of Earth-One, whose "space-brain" device accidentally bequeathed telepathic and telekinetic abilities upon her. When her brother turned criminal, her parents changed their family name to Thorul, and soon after died in a car crash. In her late teens, Lena's powers manifested and she soon became best friends with fellow orphan Linda Lee aka Supergirl. In fact, Lena impersonated the Girl of Steel more than once, and was even used as a pawn by a third lass who looked like Lena and Linda, Lesla-Lar of Kandor. Eventually, Lena joined the FBI and married fellow agent Jeff Colby. She would later be a widow and single mom, eventually learning of her brother's alias.
Liandly accidentally activate her father's teleportation device which sent her from her native planet Rolez to Earth-Two. There she met that world's Clark Kent and his wife Lois, who briefly assumed guardianship of her, and conceived of a normal name for her in the form of Linda Lee... the same name that Earth-One's Supergirl and Lena's best friend used. On her new world, she gained telepathic and telekinetic abilities which she used alongside Superman to defeat the criminal Colonel Future. As such, the hero gave her the nickname of Super-Girl. Shortly thereafter, her powers returned her to Rolez.. And that world found a parallel with the adopted world of Earth-One's Lex in Lexor!