Thorn by Intisar Khanani is currently 99c in most countries.
This is self published and I have read and enjoyed it as well as other books by the author.
This is a retelling of the The Goose Girl fairytale, so if you like that sort of book you may enjoy this.
https://www.amazon.com/Thorn-Intisar.../dp/1470181339
https://store.kobobooks.com/en-us/ebook/thorn
For Princess Alyrra, choice is a luxury she’s never had … until she’s betrayed.
Princess Alyrra has never enjoyed the security or power of her rank. Between her family’s cruelty and the court’s contempt, she has spent her life in the shadows. Forced to marry a powerful foreign prince, Alyrra embarks on a journey to meet her betrothed with little hope for a better future.
But powerful men have powerful enemies—and now, so does Alyrra. Betrayed during a magical attack, her identity is switched with another woman’s, giving Alyrra the first choice she’s ever had: to start a new life for herself or fight for a prince she’s never met. But Alyrra soon finds that Prince Kestrin is not at all what she expected. While walking away will cost Kestrin his life, returning to the court may cost Alyrra her own. As Alyrra is coming to realize, sometime the hardest choice means learning to trust yourself.