Studies show that mothers' time in particular activities with children is positively associated with child well-being, but results are mixed regarding associations between child outcomes and the sheer amount of time that mothers spend with children. Using data from three waves of the Panel Study of Income Dynamics Child Development Supplement (N = 2,622), the authors assess whether gains from mothers' total time with children vary by the quality of mothers' other investments in children or the “parenting package.” Mother-child shared time was associated with children's broad reading scores and adolescents' externalizing behavior, but mothers' other parenting investments did not moderate these associations. Results were robust to alternative measures of mothers' time and to the incorporation of earlier assessments of child academic and behavior problems. Parenting investments may be indicative of the quality of children's home environments, but do not magnify gains from mother-child shared time.