Bests & Worsts Reviews from Amazon

I bought this book for my daughter, who's almost 4, because she started to ask questions about how boys' and girls' bodies are different, and I wanted some simple anatomy illustrations to aid our discussion. I find it exceedingly odd that a book called First Human Body Encyclopedia never mentions the penis, not even within the context of the urinary tract. Four whole pages are devoted to the urinary system, but there's not a single description or diagram to help me explain why boys pee standing up and girls pee sitting down. There's also a section on reproduction, complete with talk of eggs, sperm, the uterus, and fallopian tubes, and even a female reproductive diagram to go with it, but no vagina. How is that even possible? Is it some sort of last-ditch effort to help mom and dad avoid questions about sex? They're such glaring omissions that I can't give this book a high rating, even though it's well written overall.