Mother-child reminiscing about past emotional experiences is one aspect of emotion socialization that facilitates child socio-emotional and cognitive outcomes. To advance understanding of the multidimensional nature of this clinically significant transdiagnostic process, the current investigation examined the structure of maternal reminiscing and how emergent factors related to child outcomes across two diverse samples (total N = 337). Sample one included 102 mothers and their preschool-aged children from community agencies, and sample two included 235 mothers and their preschool-aged children, the majority of whom had experienced substantiated maltreatment. Dyads completed a reminiscing task coded for multiple aspects of maternal reminiscing style (frequency and scale-based coding), assessments of child receptive language and internalizing and externalizing problems, and measures of parenting. Factor analyses confirmed that maternal reminiscing was best defined by three factors: (1) structural elaborations, (2) emotional attributions, and (3) sensitive guidance, and this three-factor structure was invariant across samples, maltreatment, maternal race, and child sex. When controlling for other dimensions of caregiver-reported parenting behavior, reminiscing sensitive guidance was significantly positively associated with child language and negatively with child internalizing and externalizing symptoms. In contrast, emotional elaborations were associated with higher child internalizing concerns. When controlling for caregiver-reported parenting and observed maternal sensitivity, structural elaborations negatively and emotional attributions positively related to child internalizing symptoms, whereas reminiscing factors did not significantly predict child externalizing symptoms nor child language. Distinct aspects of maternal reminiscing behavior are differentially related to child outcomes. Limitations and implications for understanding and measuring emotion socialization interactions are discussed.