I have a few nieces and they all started shaving at much younger ages than we did. I was shocked, but at the same time, I can understand. I wasn't allowed to start shaving until I was older and I had hairy legs. When I made cheerleader in 7th grade, they all made fun of me because my legs were so hairy and they didn't want to hold me in stunts and things, so I know the feeling. I started shaving without telling my mom. She found out and wasn't happy, but she understood. I guess my point is, if you don't let her, she will eventually sneak and do it. If you show her how, you wont lose the trust and bond you have formed with her. She will know she can count on you and come to you to help her through important things in life. If you tell her no and she sneaks, there is already a break in trust and it will make it easier for her in the future to lie if she wants to. She'll feel like you wont understand and then she'll go to her friends instead of you. The other girls will definitely tease her. Especially now days. Girls seem to be meaner than when we were in school. I know it's hard, but you have to let her grow up. Good luck!