I'm searching your mutual memories here. I am doing a sex ed course with my daughter through the Unitarian Church, and while it is awesome and much better than school versions of the topic, I'd still be curious to know if there are any sex ed / how a baby is born / learning about your body types of books that are very inclusive. We have a bunch of these books, but they still talk about somewhat stereotypical gender roles and heterosexual sex.
Granted, my daughter is only 5, but I've made a big effort to have a good selection of GLBT-friendly picture books and this is one area where there is a gap. Can you think of any books like this?