Mary Marvel precedes a personage from DC Comics.
Mary Marvel is a fictional character 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 ( cover-dated Dec. 1942 ) . 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 .