I have twins of 8 years old and they're starting to get a little hormonal! My side of the family has a history of starting puberty early (I was only just 9 when my periods started and had a 32B bust!) and I want the girls to start being prepared for the changes that may happen quite soon. Can anyone recommend a suitable book that I can use as a back-up tool to illustrate what I have to tell them or which they can read for themselves after we've talked?