Maternal education is a strong correlate of children's language, cognitive, and academic development. In most prior research, mothers' education has been treated as a fixed characteristic, yet many mothers, particularly economically and educationally disadvantaged mothers, attend school after the birth of their children. In the present study, we use longitudinal data from the National Institute of Child Health and Human Development Study of Early Child Care and Youth Development to consider whether increases in maternal education are associated with concurrent improvements in children's school readiness, language skills, and the quality of home environments at age 3. Increases in mothers' education are linked to young children's expressive and receptive language skills but only among mothers with initially low levels of education. Increases in education are also associated with improvements in some aspects of children's home environments, particularly mothers' responsiveness and the provision of learning materials. Mediation analyses provide some evidence that improvements in children's language associated with increased maternal education are due in part to changes in the quality of home environments.