["Family Relations, Volume 75, Issue 2, Page 1392-1408, April 2026. ", "\nAbstract\n\nBackground\nThis study examined the main and interactive effects of experiential avoidance and emotional support from families of origin and in‐laws on the parental psychological flexibility (PPF) of mothers of preschoolers. PPF is a key component of parenting quality and is closely linked to child development. Although experiential avoidance has been identified as a psychological factor, few studies have examined the role of family emotional support, and none have distinguished between support from family of origin and in‐laws.\n\n\nMethod\nThis study used self‐reported data from 335 Chinese mothers of preschoolers and hierarchical regression analyses.\n\n\nResults\nHigher experiential avoidance was associated with lower PPF. Emotional support from family of origin was positively associated with PPF, whereas support from in‐laws was negatively associated with it. A significant interaction showed that among mothers with high experiential avoidance, greater support from in‐laws was related to lower PPF.\n\n\nConclusion\nThis study provides a comprehensive examination of factors—both psychological and environmental—related to PPF. It highlights the complexity of family support systems by showing that support from family of origin may be beneficial, but support from in‐laws may not.\n\n\nImplications\nInterventions to enhance PPF should address both individual psychological factors and the source of family support.\n\n"]