<p>The dominant “good mother” discourse prescribes that mothers be devoted and loving, and enjoy looking after their children. Such expectations can make it difficult for mothers to navigate their negative and ambivalent feelings related to the maternal role without self-judgment and shame, adversely impacting their mental health. This study explored the associations between mothers’ ambivalent feelings and symptoms of depression and anxiety, considering the mediating roles of shame and self-compassion, and the moderating role of good mother ideals (i.e., the gap between mothers’ self-evaluation and the ideal or socially expected mother). Mothers (<i>N</i> = 499) of children 0 to 5 years in the United Kingdom completed online questionnaires. Parallel mediation and moderated mediation analyses tested the associations between study variables. Greater unmanageable maternal ambivalence was associated with higher levels of depression and anxiety both directly and indirectly through increased feelings of shame and reduced self-compassion. Discrepancies between how mothers evaluated themselves compared to an “ideal mother” exacerbated the effect through shame, also increasing unmanageable maternal ambivalence. These findings indicate that both psychological and sociocultural factors may contribute to the psychological consequences of maternal ambivalence. This research highlights the need to better understand and validate ambivalent feelings in the context of motherhood to promote maternal well-being.</p>