I am trying to remember a book I read a long time ago. From what I remember: a girl leaves her house in orange groves because of war and is sent to live with her uncle in the desert I believe. She is bored with the other girls there and spends her time riding her horse. Her uncle is some sort of military man. There are another sort of people who come on horses, and she ends up getting kidnapped. They have some sort of magic I THINK and giant cats... She learns how to fight with a sword and learns their ways.. Earns a sash to prove her worth through various trials while they are on their way somewhere... I think there is a greater enemy they are fighting.. and ends up falling in love with their king. I think the cover was orange and blue. Help! Thanks