The goal of this research was to examine links between romantic relationship experiences and other family relationships (including parent-offspring and inter-parental relationships), and included three studies that addressed this theme during different stages of development. Study 1 examined dimensions, predictors, and correlates of adolescents’ perceived power in their romantic relationships. Global power, emotional investment, and availability of relationship alternatives were identified as three distinct indices of power among 199 adolescents aged 14 to 19. Gendered characteristics and family and individual resources one to two years earlier were investigated as predictors of power, and concurrent adjustment correlates of power were examined. Results supported a resource perspective on relationship power more consistently than a gender perspective, in that positive family and personal characteristics were associated with having equal or more power in romantic relationships. Greater power was negatively related to internalizing symptoms but positively related to externalizing behaviors. Study 2 examined longitudinal associations between couple violence and parenting and coparenting experiences across the transition to parenthood. A community sample of 162 couples reported on violence in their relationships when they were expecting their first child, and reported on their parenting stress, parental efficacy, and coparenting after the child was born. Mothers’ and fathers’ violence perpetration was related to both parents’ parental distress and coparenting. Couple relationship distress, and to a lesser extent parent physical and mental health, mediated the links between violence and parenting and between violence and coparenting. Study 3 extended family systems research on associations between intergenerational coalitions in the family and the quality of marital relationships. Specifically, longitudinal links between incongruence in mothers’ versus fathers’ differential treatment of adolescent-age siblings and parents’ marital quality were examined. Multilevel models, examining 200 families over 4 waves spaced across six years, tested whether incongruence in differential parent-offspring intimacy and conflict predicted trajectories of mothers’ and fathers’ reports of marital conflict and satisfaction, and vice versa. Analyses showed that changes in interparental incongruence covaried longitudinally with changes in marital quality and that these linkages became stronger over time. Together, these three studies provide a picture of the associations between features of romantic relationships and characteristics of other family relationships in adolescence, early adulthood, and middle adulthood. Further, findings from this work can inform prevention and policy efforts aimed at strengthening family and romantic relationships and preventing relationship problems such as conflict, dissolution, and violence.