The body starts to develop years before you get your period. I got my period in fourth grade, as did my sisters, my mother, my grandmother. I was in a bra, a real bra, in third. My daughter started wearing a training bra in third and started developing, as you're describing, in second. Precocious puberty may be a growing problem nationally, but it also could just be that she's developing on track. Also, bear in mind, that a girl with a little more padding on her body will enter puberty earlier, because fat cells harbor estrogen, so if she has any extra weight on her, she may start earlier. In my family, she would be considered completely normal. And all the girls in my family are skinny and tiny -- my 10 year old weighs 62 pounds. But if no one else is developing early and she is a skinny 6, you might want to have her seen. And One and Done is right about the stalling on the growth chart -- they stop growing a year after they get their period, typically -- All the women in my family are under 5'2", but again, genetics vs. precocious puberty? I'd say genetics... After all, all the men are under 5'7".