I haven't read all the posts but I think I would explain to her that just because other girls do doesn't mean that she might be ready to. If during your discussion you feel she actually has a need to shave I'd let her. If not then there is really no sense to let her yet.
My girls are totally different and developed differently. Therefore they started doing things at different ages. One started her period at 10!!!! the other at 13, but that's another topic.
Growing up is hard.
good luck mom you're doing great