I can’t remember the name of this book, I read it in high school and it’s bothering me that I can’t place the title.

I don’t remember much about the whole book itself. In the beginning there’s two siblings, a sister and a brother. Their town was burnt down and the king (I think) was only taking males, so the brother cut his sister’s hair in a last ditch effort to save her life. She had to train to be part of the royal guard and had to bind her chest everyday so nobody figured out her secret (Mulan type stuff) and her brother ends up dying or something. It was definitely a book for young adults but I can’t remember anything else about it.