Claim: Mary Marvel was created by an author of comic books.
Evidence: Mary Marvel was one of the first female spin-offs of a major male superhero , and predates the introduction of Superman 's female cousin Supergirl -LRB- also created by Otto Binder -RRB- by more than a decade.
Otto Oscar Binder -LRB- August 26 , 1911 -- October 13 , 1974 -RRB- was an American author of science fiction and non-fiction books and stories , and comic books.