Gender in speculative fiction
The first known female superhero is writer-artist Fletcher Hanks's minor character Fantomah, an ageless, ancient Egyptian woman in the modern day who could transform into a skull-faced creature with superpowers to fight evil; she debuted in 1940 in Fiction Houses "Jungle Comics".
Power Girl
Power Girl, also known as Kara Zor-L and Karen Starr, is a fictional DC Comics superheroine, making her first appearance in "All Star Comics" #58 (January/February 1976). Power Girl is the cousin of DC's flagship hero Superman, but from an alternative universe in the fictional multiverse in which DC Comics stories are set. Originally hailing from the world of Earth-Two, first envisioned as the home of DC's wartime heroes as published in 1940s comic books, Power Girl becomes stranded in the main universe where DC stories are set, and becomes acquainted with that world's Superman and her own counterpart, Supergirl.