Mothers' mental-state references predict individual differences in preschoolers' false-belief (FB) understanding; less is known about the origins of corresponding variation in school-age children. To address this gap, 105 children completed observations with their mothers at child ages 2 and 6, three FB tasks and a verbal comprehension test at age 3, and five FB tasks at age 6. Seventy-seven of these children completed five Strange Stories at age 10. Individual differences in mothers' cognitive references at child age 2 predicted variation in children's FB understanding at age 6 and Strange Stories scores at age 10 (controlling for number of mothers' turns and children's mental-state references, verbal comprehension and FB understanding at age 3, and mothers' cognitive references at child age 6).