I also read Every Bird a Prince.

The moral is a bit obvious, even for kidlit - no, especially for kidlit, where 95% of the morals are already some flavor of "be yourself", but I'm giving it a pass for being the one and only middle grade I've ever read with an explicitly ace protagonist. Actually... I don't think I've ever read a book for ANY age group with a discussion of asexuality. It's clearly filling a gap.