In humanitarian contexts, family functioning may have a positive influence on outcomes of mental health and wellbeing for both children and adults. This study sought to adapt and explore an existing family functioning measure for use in eastern Democratic Republic of Congo. Cross-sectional data were collected from 394 respondents (196 men and 198 women) in North Kivu, DRC. The Feminist-Grounded Family Functioning Scale was developed through qualitative research and cognitive testing which conceptualized a healthy and functioning family as one without gender and power hierarchies. Generalized linear mixed models stratified by gender assessed the association between family functioning and demographics, conflict experiences, and correlates of interest including gender attitudes, acceptance of harsh discipline, positive parenting, and power sharing. In the final adjusted models, family functioning among women was associated with positive parenting (β = 0.32, p = 0.009) and power sharing (β = 0.24, p < 0.001), but attitudes around gender and harsh discipline did not retain their significant association. Similarly, men’s family functioning was significantly associated with positive parenting (β = 0.41, p = 0.011) and power sharing (β = 0.16, p = 0.014). Results suggest that family functioning is positively associated with behaviors indicative of non-violent and equitable relationships between family members, but that behaviors might be attenuating the influence of attitudes on family functioning, as the significant association between attitudes and family functioning in the univariate models was not retained in the full models accounting for both behaviors and attitudes. Further research is needed to capture the context-specific nuances of family functioning and to understand the influence of gender and power hierarchies for families in conflict settings.