I read this a couple of times between the ages of 10 (in 2003) and 14, mostly just certain sections but a couple of times all the way through.
My biggest complaint is that the book is outdated and perpetuates myths such as lesbianism being described as "a choice of lifestyle" which just isn't true, and as a bisexual pre-teen was really baffling to me. There was also the matter of "The dangers of promiscuity" which yes, there are plenty - STD's, unwanted pregnancy, legal ramifications if someone is underage, lack of self-worth etc but:
You are greatly increasing the risk of hurting other people who don't approve of what you're doing
Seriously?
There were some things I liked, such as pointing out that the hymen can break during sports (though it is implied that hymen = virginity so by that logic riding a damn horse as a child means you're no longer a virgin which is absurd), how to report sexual assault, types of contraception etc but that didn't make up for how outdated and pretentious it was.
I got this for my daughter off Bookmooch.com who was going to be turning 11. But I was SHOCKED at what was in it. There were things in there I thought a young girl didn't need to know.