This study analyzes the role of positive parenting, encompassing affection, responsiveness, encouragement, and teaching, on 79 children’s negativity aged 10 to 24 months during interactions with their adolescent mothers (aged 15 to 21). Parenting behaviors were evaluated using the Spanish version of the Parenting Interactions with Children: Checklist of Observations Linked to Outcomes (PICCOLO). Maternal well-being was assessed using the Spanish version of the Hospital Anxiety and Depression Scale (HADS). At the same time, the Ages and Stages Questionnaire-Socioemotional Development (ASQ-SE) measured mothers’ perceptions of their children’s socioemotional development. Children’s negativity was assessed using the Subscale of Negativity from the Early Head Start Research and Evaluation Project (EHSREP Negativity Subscale). Bivariate analysis revealed a significant association between maternal affection, responsiveness, encouragement, higher maternal anxiety, and maternal perceptions of their children’s socioemotional development with children’s negativity regarding anger, hostility, or dislike toward their mothers during interaction. Moreover, multivariate regression analysis showed that maternal affection, responsiveness, anxiety, and perceptions of children’s socioemotional development could predict negativity. The study underscores the significance of positive parenting, maternal well-being, and perceptions of children’s socioemotional development to prevent high levels of children’s negativity.