The Kestrel by Lloyd Alexander

This is the sequel to Westmark, and I gave it a rating of four out of five. Mickle becomes queen when her father dies, and traitors conspire with a neighboring force to take over the kingdom. Mickle leaves the castle and ends up leading her forces in battle. Theo also gets involved in the war movement, which creates a conflict because he wasn't able to make himself fire a gun in book one to save his friend, Justin. Theo becomes a battle officer and helps lead the forces against the enemy. Mickle comes up with a plan for peace, but it's side-tracked by a big battle in the story's climax.

I enjoyed the conflict and plot, and it created suspense when Mickle secretly left the castle to join the battle. There were many twists and turns to the plot, but I found the setting changes a little confusing at times. Maybe it was just me. I enjoyed the thoughts and actions of the two orphans. They shared a naive view of war and added some humor with their actions and dialogue. They were also important participants to ending the war.