Despite well-documented behavioral changes, the development of neuropsychological substrates underlying inhibitory control remains unknown, hindering understanding of this construct over time. Stability and change in N2, a neural correlate of inhibitory control, and its crosslagged, bidirectional associations with maternal emotion characteristics were examined in 121 preschoolers (59% female, predominantly White) between 2014 and 2017. N2 was stable from 3 to 5 years of age. Greater maternal negativity at age 4 predicted smaller N2 amplitudes in preschoolers at age 5 ([beta] = 0.22); preschoolers' N2 amplitudes did not predict subsequent emotion characteristics in mothers. Findings provide initial evidence for mother-to-child, but not child-to-mother effects linking N2 with mothers' emotion characteristics and a foundation for future longitudinal work on developing neural correlates of inhibitory control in preschoolers.