Although maternal employment has long been linked to children's later labor market outcomes, most research treats employment as a static status rather than an evolving process across childhood. This study reassesses the relationship between maternal employment and adult children's labor market participation by adopting a trajectory-based perspective that captures the dynamic nature of mothers' work patterns, with particular attention paid to timing and intensity. Drawing on mother-child dyadic longitudinal data from the National Longitudinal Survey of Youth (1979) (NLSY79) and the NLSY79 Child and Young Adult (n = 2,186), this study applies sequence analysis to classify distinct patterns of maternal employment trajectories across children's childhood and random-effects multinomial logit models with inverse probability of treatment weighting to assess how these trajectories predict adult children's labor market participation. Five trajectories emerge: continuously full-time, early return, late return, part-time, and not working. Relative to continuously full-time employment, a not-working trajectory is associated with a substantially higher likelihood of non-employment in adulthood for both sons and daughters, though the association for sons weakens after accounting for pre-birth family background. Parttime and late-return trajectories predict higher odds of reduced employment only among daughters. These findings underscore the gendered nature of intergenerational transmission in labor market participation.