In Western patriarchal culture, the Good Mother is traditionally framed as rigidly self-sacrificing, submissive, and fulfilled in her role as "foundation parent," but this is an idealised and damaging view of motherhood in the patriarchal imaginary. This romanticised maternal archetype has found expression and been promoted in popular screen media, setting an impossible example for women audiences. I argue that these destructive constructs require reassessment, in relation to the intersection of motherhood, personhood, and the patriarchal. One film to depart from such representations, and the subject of analysis in this paper, is Maggie Gyllenhaal's The Lost Daughter (2021). The film presents a searingly complex portrayal of motherhood and, according to the director, was used to explore maternal representation, feminism, and constructs of the Bad Mother. Through a close analysis of maternal figures, I argue that the film ultimately presents a radical and destabilising cinematic (m) other image which critiques and disrupts the deeply entrenched patriarchal control within the identity of the Mother.