Hey, what about Wonder Woman's Golden Age villainess? Like Hypnota, Blue Snowman? I am sure there are more, that I may missed.

I remember one deceased hero from Justice League Task Force - her name is Mystek and she dressed like a man, to conceal her identity. Also, I remember the story in Justice League Quarterly, the woman was transformed into a man and hmmm, can't recall the whole story. sheesh!