I mean, the author himself is trans. I'm assuming the author used his own personal feelings/interactions to guide the characters. I haven't read anywhere where he says that because i don't follow authors that closely, but it makes sense to me for that to be the case. Being trans is a major part of your life and who you are and can effect everything, especially if you have a family who isn't supportive.

In the instance of this book specifically, the magic system is based on gender so it makes sense for it to be mentioned as often as it is strictly because his family doesn't believe or support his transness. I think some people want to know the character is trans without being reminded how all-consuming it can be in your life. But that just simply isn't the case for a lot of trans people. There's unfortunately always going to be some people who aren't happy with the representation of a specific group regardless of what that group is, and I think a lot of it has to do with not realizing how vast the experiences can be for each individual person in that group.

I loved this book. I loved the representation and how real it was and I loved the growth of the characters.