Some of my fave GA heroines? Let's see...
Harvey's Black Cat...definitely!
Fiction House's Camilla, especially as drawn by Fran Hopper.
Senorita Rio done by the Eisner Shop. Don't miss those two stories!
Lady Luck...fine and funny.
Fiction House's Futura...one heck of a heroine, in the tradition of Hunt Bowman and Killraven, kinda.
DC's Black Canary.
Timely's Namora. Bill Everett could draw women like nobody's business. Might add Venus to this one, but I like Namora better.
I'm sure I'll think of more later.