http://en.wikipedia.org/wiki/Women_in_warfare_and_the_military_in_the_ancient_era
Wiki article, solly. Still, quite a list here. And no one knows about it. Well, very few; anyway.
If they can handle it, if they wanna go, if they're stupid enough to face the crap the military dishes out including getting raped by the idiot sausage casings operating only on instinct with issues; let 'em go. Maybe they'll get killed before they breed to pass down the 'stupid' gene.