I started my period right after my 10th birthday, and had been having breast tenderness and needing to shave for 2 years before that. By my 11th birthday, I was completely developed and wearing a full C-cup bra. Not very pleasant for being so young..... I think I definitely had some hormonal issues going on at a very young age. When I was 13, I had a period for 4 months straight. What's crazy now is I've never been able to get pregnant after 8 years of trying and they can't find a reason. I wish I'd been checked out for hormonal issues when I was younger - maybe they could have done something? I'd bring your daughter in if you keep seeing signs of too early development...it certainly wouldn't hurt.