I really enjoyed this with the story of "streghe" or "strega," magical beings / people who can pretty much change their bodies into any sort of person or animal. Of course, magic comes at a cost, as this story makes clear and the impetus for the whole book is for our heroines / heroes to make some sort of peace with the bad things in the past that helped to shape their lives.
Depending on the situation, the two main streghe of the story flip back and forth between being male and being female in pretty quick succession. I liked the fact that the questions of sexual identity in this story were in a creative science-fiction or fantasy context. It wasn't just a theme inserted into a YA book to make the book part of a marketing "niche."
You have some wicked royals here, with our heroes / heroines having to find some way to bring freedom or justice to this alternate-universe medieval-ish Italy-ish time and place.