Mothers experiencing psychological distress in the postpartum period may have difficulties parenting their children. Inconsistent and unresponsive parenting may increase the risk of later emotional and behavioural problems in children. The purpose of this study was to identify how maternal psychological characteristics cluster at eight weeks postpartum, and whether these clusters were associated with maternal-reported child emotional and behavioural problems at the age of three years, as measured by the Parents' Evaluation of Developmental Status (PEDS) questionnaire. In a longitudinal pregnancy cohort (N?=?647), three clusters of postpartum psychological characteristics were identified. Contrary to expectations, mothers with the greatest psychological distress did not report concerns about their child's emotional and behavioural problems; rather, they reported concerns about global developmental delay. These findings suggest that infants of mothers experiencing postpartum psychological distress should receive additional follow-up to reduce the risk for global developmental delay.