I don't have those books, but this is how it did turn out here with one child particularly. But when he asked about intercourse (in a way that felt so out of the blue), I wished I had a book to show him while we talked. I explained as naturally, and well, as I could. Then I purchased some books. My plan was to use them whether asked again or not, but I haven't found one that's enough information without being too much information for him. I liked a lot about the It's Perfectly Normal linked in this thread, but it was too much information (down to types of intercourse and birth control) for my pre-teen. Their younger book wasn't quite enough for him. I wish I could merge parts of each. The other books I found were also not enough or not quite as positive as I would like to be.
I think some kids are more willing to ask questions. Others you'll need to take the initiative. And I agree with trying to be the first source of information, which means you'll need to hit it relatively young depending on her contacts and activities. I was surprised how much kids talk about this stuff at ages younger than I remembered growing up.