Honestly, I'm looking for this novel for my mother. She read it a few years ago and has been looking for it again recently.
So the protagonist is a girl whose twin had passed away. The story plays out in a medieval middle-east type setting, with deserts and castles. The girl is captured and held captive by a prince.
Through some turn of events the roles change, the prince is injured and the girl has to look after him.
Finally, plot twist,
the prince is a girl
Does this sound familiar to anyone? The book was published in the 90s.