So... one book about a boy who wants to imitate mermaids, a couple of books that acknowledge to children in a non-detailed way that transgender people exist at all, and books like Gender Queer [1] and This Book Is Gay [2], which are targeted at the junior high and up age group and have basically the same level of explicit detail as the sex ed courses those kids have already gone through (but are, I guess, somehow extra evil because they feature gay people).

Looks like the standard brand of 'gender nonconformity is the same thing as making third-graders watch porn' bullshit to me.

[1]: https://en.wikipedia.org/wiki/Gender_Queer

[2]: https://amazon.com/This-Book-Gay-Juno-Dawson/dp/1492617830