Numerous empirical studies have found that maternal educational attainment is correlated positively with desirable outcomes for children, including academic achievement. At the same time, little is known about the effect of the timing of mothers' schooling on the same set of child outcomes. Using the Early Childhood Longitudinal Study-Kindergarten Cohort (ECLS-K), I find a positive effect of full-time maternal post-secondary enrollment on the reading scores of kindergarten students after controlling for child-specific, time-persistent unobserved heterogeneity. This effect is especially strong when the sample is narrowed to children with married mothers or in households where a father is present. No similar effect is found for kindergarten math scores. (Contains 4 tables.)