My daughter hit puberty early at about 9. Periods started when she was just 10 ( apparently you have to be a certain per centage of adult weight or certain weight for that to happen). She says "It's not a real problem... the others will catch up eventually". She's 11 now and the others are beginning to catch up. If you don't make it a big issue it won't become a big issue. There's not much you can do about it. It's not that abnormal. My daughter says "If she's not making a big deal about it, then it isn't actually a big deal. My daughter is about the youngest in her year and I think was the first to have periods but by the end of year 6, there were a handful of girls in the same position.
I have a 10 year old who has no signs of puperty yet, but she has engaged in sex play with a boy her age...which had me in a fit.
After this encounter I sat her down and told her about the birds and the bees strait away. Young girls need to know about these things before their periods start and I have read that this can happen as early as 8 years old?? What is the reason for this madness?