I'm as GC as the next person, but I don't think there's anything wrong with a book supporting children with a trans parent.
From the blurb though, this sounds more like its about a child supporting their trans parent. She's a 'shy' child but has to 'find her voice' and 'face her fears' not to benefit herself but in order to protect and validate the feelings her father? Just... No.
A female child having to put in lots of work in order to protect the feelings of her male parent is really quite misogynistic and sends the message that the feelings of adult males take priority over the feelings of children. Which can actually be a very dangerous message and is a message used by groomers and abusers all the time.
I admit I haven't read the book so I don't know how the story goes, but that synopsis does not fill me with hope