Using longitudinal data from the Fragile Families and Child Well-being Study (N = 1,162) and the National Evaluation of Welfare-to-Work Strategies (N = 1,308), we estimate associations between material and instrumental support available to low-income mothers and young children's socioemotional well-being. In multivariate OLS models, we find mothers' available support is negatively associated with children's behavior problems and positively associated with prosocial behavior in both data sets; associations between available support and children's internalizing and prosocial behaviors attenuate but remain robust in residualized change models. Overall, results support the hypothesis that the availability of a private safety net is positively associated with children's socioemotional adjustment.