The Girl Who Drank the Moon by Kelly Barnhill.
Every year the people of the Protectorate leave a baby in woods as a sacrifice to a witch, believed to live in the forest. Unknown to them, the witch rescues the babies and sees to their safety. But one year this routine goes wrong and the baby winds up infused with moon magic and too dangerous to be adopted, so the witch takes her to raise. This sequence of events leads to great changes for everyone–baby, Protectorate, the witch, and her companions.
Winner of the 2017 Newbery Medal.