How many boys wait to start pulling their Willie's till after they are 12??? It's IMPORTANT for girls as well to get to know how their sexual tools (read: vagina, pussy, w/e you call it) works BEFORE they start having actual sex. And many, more than you think, would have accidentally aimed the shower head down there by that age, figuring it feels good. So the choice is to leave them to discover this on their own in secret, or to give them a sense that nothing about this is unnatural or wrong. And you can do that by giving them access to a tool that let's them discover how it works, perhaps even have an orgams (I know, a girl orgamsing...!!) BEFORE their first awkward 1 on 1 with a boy or a guy.