Young mothers formerly associated with armed forces and groups (CAFFAG), and their children constitute an under-researched group within the literature on children affected by armed conflict. This chapter sought to understand what happens in and through relationships in a longitudinal participatory action research study with war-affected young mothers including former CAFFAG young mothers. The chapter takes as a starting point Martín-Baró’s (1989) observation that trauma is social and links this with new theoretical frameworks within sociocultural psychology on relating and ‘relational being’ (Gergen, 2010). The study aimed to learn what successful social reintegration meant for young mothers and to help them to achieve it. Participants were 658 young mothers and over 1,200 of their children in Liberia, Sierra Leone and Northern Uganda. Findings show how the PAR created sites of ‘joint action’ (Gergen, 2010) between young mothers, advisers, community members and local leaders. It acted on the core relational abilities identified by Martín-Baró as impoverished by social trauma with positive outcomes for their own and their children’s development and that of their communities.