I got away with standard plates, but I'm pretty small. Honestly, because we females have such diverse structures I suggest going custom with your plates. I didn't do this, but I've heard and seen other chicks taking a duct tape cast of themselves, chopping up the tape-shell, and using that as a TEMPLATE for plates.
And if you can fit the standard plates and don't want to be mistaken for a guy there are plenty of ways to make the rest of your kit more feminine but not necessarily "sexy" for you. Hope that helps!