Matilda Bone by Karen Cushman.
The "School Library Journal" Best Book of the Year about a medieval orphan's life as an assistant to Red Peg the Bonesetter.
Orphaned Matilda is not at all pleased when she arrives at Blood and Bone Alley to become an assistant to Red Peg the Bonesetter. She is a religious, well-educated girl who can’t picture herself doing dirty chores or helping sickly patients.
Each day is very different from her former quiet life. Matilda’s not used to being around so many people who are coming and going, laughing and eating. Not one of them seems interested in prayer or study.
Self-centered Matilda thinks no one understands her. But Peg does, and gives her time to get used to this new way of life and teaches her through kindness and friendship. Matilda is as surprised as anyone when she begins seeing the world around her in a different way.
This book is used in Illuminations.