I read through this before giving it to my daughter and was very impressed with the matter of fact tone of the writing. Covering everything from tracking your menstrual cycle to breast self exams to what's happening to boys at this age to slang words for body parts, I would have LOVED to have access to this book as a young teenager. I remember feeling very stupid about the subjects covered here and let's face it, most of us are too embarrassed to ask about or discuss these issues in the depth found here no matter what our age! I do think it is likely to be too much information for the younger end of the suggested age range which is 9-15.
I read this book as a 4th grader and LOVED it. The authors never talks down to the reader and presents information in a straightforward manner.
I was a mature 10-year-old, so I didn't find it "too graphic," as others have mentioned in other reviews. In fact, I loved that the authors spoke to me in factual language and included relevant and clear illustrations when needed.
If you want your daughter to have straightforward, clinical-yet-approachable information, then this is a fantastic book.