Mary Marvel is a spin-off of a character from a cave.
The Marvel Family , also known as The Shazam Family , are a group of superheroes who originally appeared in books published by Fawcett Comics , and were later acquired by DC Comics . Mary Marvel . 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 ( also created by Otto Binder ) by more than a decade .