Now that my boys are both teenagers, we've got a lot more YA stuff around the house. I've started on Alison Goodman's Eon--and, Wow. Great world-building, great use of Chinese mythology, really interesting exploration of gender roles and identities. It isn't just girl-pretending-to-be-boy. The main character has been pretending for so long, she no longer thinks or feels like a girl. And a secondary character is transgender--male dressing as female--who plays a special, unique role within the court, being able to serve as advisor to men, which other women can't, but also being able to spend time with the women of the harem without being a eunuch.
Some really fascinating themes that take it beyond typical action/adventure dragon fantasy.
Highly recommend it.