The goal of the Prime Family Lab is to understand and support child mental health and development using a family framework. We examine how children's family environment influences, and is influenced by, children's development and mental health. We consider the family as a system, made up of multiple, interdependent parts, including interparental, parent-child, and sibling relationships. We study the contexts that surround families, and how programs, policies, and communities can support families to thrive. Finally, we design and evaluate programs to build strong relationships and engage with one another in a way that promotes the well-being of children and their families.