Erk, tampon page??

I am thinking of getting this book for Suki, 12. She has full boobage, hair growth, and smelliness, but no period yet. I am pretty open about things, but I think a good explanatory book would help, too, and I have heard good things about this one.
So, just how in depth do they go? She is homeschooled, too, and pretty sheltered in regards to a lot of things to do with the uhh...reproductive functions, and I don't mind keeping it that way for a little longer. I don't mind her knowing things like the functions of the ovaries and stuff, but a description of exactly how a baby is conceived would prob be a *leetle* too much for us, lol.