The extent to which the influences of family-systems intervention practices could be traced to variations in parent–child interactions and child development was investigated by meta-analytic structural equation modeling (MASEM). MASEM is a procedure for producing a weighted pooled correlation matrix and fitting a structural equation model to the patterns of relationships in the data. The main practices constituting the focus of analysis were capacity-building help-giving practices, social supports and resources, family needs (concerns and priorities), and family strengths. Eight studies were included in the meta-analysis. The participants were 910 infants, toddlers, and preschoolers with and without developmental delays or disabilities and their parents or other primary caregivers involved in different kinds of help-giving programs. Results showed that capacity-building help-giving and family-systems intervention practices had direct effects on both parent self-efficacy beliefs and well-being and indirect effects on parent–child interactions and child development mediated by self-efficacy beliefs and parent well-being. Implications for practice and further research are discussed.