I thought it was a nice book and don't see anything wrong with having a child read this like-
I saw so much of my younger self in this ( and also lots of parts i didn't that's ok too! ) it's just nice having more nonbinary stories out there for young trans folks to learn from.

Also warning to readers. There's lots of harry potter mentions but I'm pretty sure this came out before all the transphobia from JKR was public. It sucks, but it is what it is.