The Arrow and the Crown by Emma C. Fox

Ever since Anna can remember, she has avoided the ancient Grünwald Forest, where her parents disappeared years ago. Everyone in the kingdom of Weissburg knows the forest is haunted. Tales abound of vengeful spirits that lurk among the trees, and of a Beast that has taken the lives of peasants, knights, and the king’s own son. But when the Beast emerges after seven silent years to wreak havoc on the kingdom, Anna braves all her fears to confront him. She soon discovers that there's more to the Beast than she realized—and more to herself than she ever imagined.