Eon by Allison Goodman

I listened to this book on Brilliant Audio downloaded from Audible.com.  It was a great recording of the book.  It took me longer to listen to, than I would normally like with 25 chapters, but worth the time.  At the time I finished the book I downloaded the sequel, but have not had time to listen yet.  I also realized that I have not reviewed this book yet.  So, I will fix that now.
Eon is training to be a dragoneye.  He must be successful or his master/sponsor will loose everything.  However, Eon isn't Eon, he is Eona a girl and forbidden to train.  His master knows that his training puts them all at risk of death because women are not allowed to hold such a powerful position.
Eon is full of self doubt and worried someone will discover the truth. The day comes when the rat dragon will select a new dragoneye. - the author seems to use the Chinese zodiac and many ideas of Chinese culture in this book.  Eon barely makes it through the demonstration battle with one of her former trainers using her disability to make him fail.  He is a cripple due to an accident that crushed Eona's hip.  Amazingly, he makes it through the battle, but the rat dragon doesn't choose him, but it doesn't matter, because the mirror dragon does.  There has not been a mirror dragon in 500 years.  However, Eon struggles to bond with his dragon, maneuver through court politics, and show support for the Emperor.   This book has many twists and turns some predictable some not.  One of my favorites this year.