She's the granddaughter of the original Giant, the daughter of the second Giant and the Nemesis Girl, and the "twin sister" of the current Giant. She's amazingly strong, incredibly tough, and out to make a name for herself as a member of the League of Champions, and America's newest costumed heroine. One of the more interesting thing about the G-Girl is that she's also a TG superhero. She's not the current Giant's "twin sister" at all. She's actually him, magically transformed into a teenaged girl.