This research explored and compared patterns of adjustment in siblings exposed to intimate partner violence. The quality of family relationships were investigated as potential mechanisms that accounted for heterogeneity in these patterns. Participants included 47 sibling pairs and their mothers recruited from the community. Mothers and children reported on child adjustment measures and the quality of family relationships. Five cluster patterns were identified for both younger and older siblings, replicating three identified in previous research: primarily internalizing symptoms, a combination of internalizing and externalizing symptoms, and an asymptomatic cluster. There was little overlap in cluster membership within families; most siblings differed in terms of their pattern of adjustment. The quality of family relationships varied significantly across clusters. Overall, asymptomatic siblings reported the most positive family relationships. Maternal warmth differed across clusters for both older and younger siblings, while maternal hostility varied across clusters for older but not younger siblings. The quality of sibling relationships also differed across clusters for older but not younger siblings. These findings underscore the importance of examining differential sibling experiences within violent families, and demonstrate the significance of family relationships as a mediating mechanism influencing heterogeneous child adjustment.