10 Gender-Bending Children's Books You'll Love
My Princess Boy by Cheryl Kilodavis (2010)
Cheryl Kilodavis's son enjoys wearing dresses and pink spangly clothes, not because he's gay, but because pink spangly dresses are awesome! So when he announced to her that he is a "princess boy," she created this book.
It lacks a conventional story, but it shows that it's okay to express yourself, and how a supportive family can help protect a kid from gender-phobic criticism and bullying.
If anything, the books in this article all show that societial hang ups about gender and self-expression are more problematic than those who want to live as they choose.