Could it be... cookies?
It's not bad, but I'm not impressed by it. It does actually use the words "placenta" and "umbilical cord," which other books seem to avoid for some bizarre reason. It starts out pretty similar to other books-- what's the difference between girls and boys? That's not a difference... That's not a difference... Oh, it's their bodies! One interesting snippet: "You may hear all kinds of words used to talk about girls' and boys' genitals. There are personal names, silly names, even rude, insulting names called swears." And then it says, which is cool, "Find out the correct names for as many parts of the body as you can." It uses the word "vulva" instead of the incorrect "vagina." It says not to look at people when they're naked unless it's okay with them, and don't touch people if they don't want to be touched. It actually uses the word "masturbation": "Touching and rubbing your genitals to feel good is called masturbation. Some of us try this; some of us don't. However, it's best to do this private kind of touching off by yourself." A decent, if non-committal, way of describing that. It kind of mentions as an aside, "No one has the right to touch you in a way that feels wrong or uncomfortable. If you don't like the way someone touches you, speak up and tell him or her to stop. If that doesn't work, tell your mom or dad or another grown-up." It doesn't go into any more than that (like, for example, what to do if the person tells you not to tell your mom or dad).
It mentions that the "reason" that boys and girls are different physically is because that's necessary for making a baby, but helpfully adds, "However, not every grown-up is a mother or a father. You can be a woman or a man and not be a parent, if you so choose." It might not be necessary for books to mention that, but it is a nice plus. It then says, "A man and a woman fit his penis into her vagina." Which it describes as "sexual intercourse." It mentions the sperm meeting an egg, and generally the baby taking about nine months to grow, without talking about the stages of development like other books I've read recently. It does not mention cesarean section, which is weird, although it says, "In most births, the baby comes out the vagina," which makes it sound like in other births it comes out through the mouth or something.
Then it basically says that as you grow up you'll go through puberty, but have fun being a little kid now. So parts of it feel sparse compared to other books. The information it does have is accurate, but I'm probably not going to use it to teach my kids. I would understand if other parents used it, though.