Sometimes even characters with a very impressive careers can fade into total obscurity.
Betty Bates was a Prosecutor, which I assume was a very atypical career choice for a woman in the 1940s. If that wasn't, then the fact that she took to the streets to beat up gangsters certainly was. Sometimes she used classing brawling techniques, sometimes she used martial arts, and sometimes she used... a gun.
Unlike most public domain superheroes, Betty Bates had a long career, appearing in 61 issues! To put that into context, her first story (featured in Hit Comics #4) was published in 1940. Her last story (Hit Comics #65) was published in 1950! Most public domain superheroes just last, like, two years at most.