Reducing parenting stress and enhancing parental engagement in child routines are theorized as two important factors for ameliorating effects that maternal depression exerts on young children’s development. These connections are supported by behavioral parenting processes within attachment theory. Through secondary analysis of a large population of preschool-aged children, this study empirically examines the connections among parental mental health, stress, and engagement in child routine activities with children’s emotional regulatory competence. Path analysis using structural equation modeling demonstrates that maternal depression indirectly but significantly impacts children’s development. Parenting stress mediates the connection to parental engagement in child bedtime routines and to children’s regulatory competence. Parental engagement in child bedtime routines partially mediates the influence of parenting stress. The study also examines moderation effects of children’s gender and race/ethnicity. The results imply that although parents may be reluctant to seek professional help to address mental health difficulties for themselves, reducing parental stress and encouraging engagement in shared bedtime routines offers benefits to children’s regulatory competencies. Limitations of the study and future directions are considered as well.