Jay Tor

This is known as precocious puberty, here's a link:
[url="http://www.nlm.nih.gov/medlineplus/ency/article/001168.htm"]http://www.nlm.nih.gov/medlineplus/ency/article/001168.htm[/url]

Usually early puberty runs in a family. If this is not the case in your friend's family, her doctor may want to put her daughter on some meds to stop the puberty for now. There are some very good medical and psychosociological reasons for doing this.

Whenever the hormones are involved, it's usually best to consult a specialist. In this case, a pediatrician, endocrinologist or OB/GYNE associated with a good children's hospital.