Mary Marvel is a fictional character, a comic book superheroine, originally published by Fawcett Comics and now owned by DC Comics. Created by Otto Binder and Marc Swayze, she first appeared in Captain Marvel Adventures #18 in (December 1942). The character is a member of the Marvel Family of heroes associated with Captain Marvel. She is the alter ego of teenager Mary Batson (adopted name Mary Bromfield), twin sister of Captain Marvel's alter-ego, Billy Batson. Like her brother, Mary has been granted the power of the wizard Shazam, and has but to speak the wizard's name to be transformed into the superpowered 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. more info: http://en.wikipedia.org/wiki/Mary_Marvel