Family stress theories posit that individual family members are positioned to adapt to external stressors differently and that these differences can strain family systems. Analyzing in-depth interviews with a diverse sample of migrant mothers in Costa Rica, we investigate how families adjust to the stressors of international displacement. Three stages of family stress adjustment emerged from our analysis: (1) parents' prioritization of safety, (2) parents' and children's grappling with new legal, economic, and social circumstances, and (3) parents' protracted uncertainty in one or more of these realms concomitant with children's feeling resettled. A fourth stage of (4) convergent parent and child resettling also emerged, but only among select families who enjoyed stable financial or emotional support from extended kin or local institutions in Costa Rica. Parents' perceptions of their security, and social, economic, and legal circumstances contributed to the progression between stages of stress adjustment.