Objectives: We examine how the timing of children’s transitions to adulthood are associated with mother’s depressive symptoms. Mothers and children are close over the life course. However, these relationships often change as mothers age and children enter adulthood. Today, the transition to adulthood has become delayed and increasingly unstable among children with the timing of the acquisition of a college degree, full-time employment, and marriage shifting from young adulthood to adulthood. This may have consequences for mothers’ depressive symptoms. Method: Using data from Waves I, IV, and V of Add Health and Wave II of the Add Health Parent Study, we employ OLS regressions to investigate how transitions to adulthood (e.g., college completion, employment, and marriage) for children and timing of transitions (i.e., in young adulthood or adulthood) are linked to depressive symptoms of aging mothers. Results: We find children’s education was negatively associated with mother’s depressive symptoms if the adult child had completed a college degree by young adulthood, relative to those who did not attain a college degree by adulthood. However, for marriage, this transition was only significantly linked to reduced depressive symptoms if the adult child had ever married by adulthood. Our findings reveal the mental health of aging mothers is influenced by circumstances in the lives of adult children, such as acquisition of a college degree and entry into marriage. However, the timing of transitions is less important.