Maternal education is associated with early child outcomes. However, the several mechanisms that may explain this relationship remain underexplored. Using data from 1,097 children aged 12–15 months in Chile, we estimate the maternal education gap across child cognitive and language outcomes. Following a bioecological perspective, we explore potential pathways by which maternal education might influence child development, such as child characteristics, the quantity and quality of mother–child interactions, and the availability of home stimulation. We found an average maternal education gap between children with mothers with the lowest and the highest educational levels of 0.36, 0.31, and 0.25 standard deviation in child cognition, expressive language, and receptive language, respectively. The mediational analysis showed that maternal stress and depression and the quality of the home environment mediated the relation between maternal education and child language and cognitive development.