Women experience anxiety, depression, and stress at higher levels than men and have more parenting responsibilities, especially establishing health practices in the home. Given children’s vulnerability, this study aimed to increase understanding of how mothers’ mental health status relates to maternal weight-related cognitions, home food environments, and child health via a cross-sectional survey design. In a cluster analysis, using maternal anxiety, depression, and stress assessments, we placed the sample of 531 mothers of school-age children into four clusters: Cluster 1 had the best mental health status, Cluster 2 had high stress, Cluster 3 had anxiety and moderate stress, and Cluster 4 had anxiety, depression, and high stress. Our results indicate an overall downward trend in weight-related cognitions as mental health worsened. Similarly, as mental health declined, so did home food environment characteristics, such as the greater use of non-recommended child feeding practices, fewer family meals, and greater sugar-sweetened beverage supplies. As mothers’ mental health status became poorer, children’s general health and mental health quality of life declined, and sugar-sweetened beverage intake increased. Our findings suggest that maternal stress, anxiety, and depression are moderately to strongly linked with mothers’ cognitions, home food environments, and children’s health. Our results also suggest that mental health interventions for mothers should assess cognitions and home food environments and consider the extent to which these factors are affecting family health.