Out of curiosity, I decided to build a list of Golden Age female superheroes and this is the list so far. Feel free to point out anyone I missed:
Jane Arden (female reporter in newspaper comic strip) 1928 & later in comic books?
Sally the Sleuth (female detective cartoon in Donenfeld's detective pulps) 1934 & later in comic books?
Maybe they're just platinum age heroines? ¯\_(ツ)_/¯