"Kris: Female Knight" by Marissa Michele Shepherd

This is Kristine Kenslay, also known as Kris. She is the daughter of the king and queen of a fantasy kingdom called Alenia. She is a fiesty and spirited princess who has her own way. Part of that way is falling in love with the enemies son, but I can't say too much on that part of the book. It's one that I'm writing and I can't give too much away. Anyhoot, this is a part from when Kris is an adult. Her love has been kidnapped by his adoptive father for helping her escape him. She's gone after him, afraid that it's too late. She had taken a company of soldiers, but they've been picked off one by one until Kris is the only one left on this rescue mission. She's taken deep into a cave after heavy battling and is so close to finding her love.

I'm not sure if I'm going to put this part in the book, but it's a definite possibility.