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".
Supergirl (Kara Zor-El)
Although Kara Zor-El was the first character to use the name "Supergirl," DC Comics tested three different female versions of Superman prior to her debut.