The strength of this book was that it made the topic into a narrative and gave it that kind of logic. So the book does something unique beyond the information you could just get from wikipedia, and justifiex its own birth as a paper, hard-cover, four-color book. Fiona Smyth's color scheme and some of the patterns and juxtapositions are downright psychedelic, and there was a lot done in the illustration to avoid any sense of realistic portrayals--it is not a biology book, it is a book about -talking to young people- about making babies.
For a 'fact book' this story leaves more questions than it gives answers--in fact it is so indirect that a couple of times it made me think, "maybe it doesn't work the way I thought it does." This indirectness might be a plus if a reader has adults to talk to about the things that are left out (and wants to talk to adults about sex). But if this is supposed to be a more or less benign way to get the straight information on what makes a baby, the approach is way too oblique.
Ultimately, the subtitle is what subverts the experience for this book. Silverberg tries so hard to be politically neutral, it's hard to tell who he's trying to avoid offending. On the one hand he keeps everything so gender neutral, you are left to wonder whether some women have sperm and some men have eggs (bad science). Is he trying to keep things neutral for the LGBT family? Or is he trying to keep things neutral for the anti-sex-ed Christian crowd--a book about sex ed that really doesn't tell how reproduction works? Maybe both. I'm just not sure inference is the key comprehension strategy we want to rely on with this topic.