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".
Wonder Girl (Cassie Sandsmark)
Cassandra "Cassie" Sandsmark, also known as Wonder Girl, is a fictional superheroine appearing in DC Comics. Created by John Byrne, and first appearing in "Wonder Woman" (vol. 2) #105 (January 1996), she is a sidekick of the popular superhero Wonder Woman and also a prominent member of the superhero group the Teen Titans.