Sister Yu is one of the teachers at the orphanage where LuLing lives after Mother banishes her from the Liu home. She is a small, bossy, and opinionated woman who has a habit of mocking the orphans she supervises, many of whom have physical disabilities. Sister Yu loathes self-pity and believes there is always someone whose situation is worse than one’s own. Sister Yu’s impoverished childhood has made her resilient but not particularly gentle or compassionate. Still, LuLing admires Sister Yu’s strength and partially names Ruth after her (Ruth’s full name is Ruth Luyi Young).