The paper investigates the relationship between mother's education and her parenting using data from the child supplement of the 1958 National Child Development Study (NCDS). By considering data across generations, our dataset allows us to estimate the size of the bias in the relationship between education and parenting from failing to account for background characteristics, early cognitive development and mother's own parenting experiences. The subjects were 1,182 longitudinally sampled mothers of 1,879 children aged between 3 and 18 years old and divided approximately equally across gender (51% sons, 49% daughters). Controlling for a wide range of family background variables and mother's own achievement prior to 16, results indicate a confounding bias of 73% for cognitive stimulation and 89% for emotional support. This confounding bias is larger for daughters than for sons. Even after the inclusion of a large set of controls, a small effect of maternal education on parenting, assessed in terms of the provision of a cognitively stimulating environment, remains statistically significant but only for sons. Although educational effects estimated here suffer from downwards bias owing to under-representation of older mothers within the data, some unobserved factors could remain as a source of bias. (Contains 3 figures, 4 tables, and 2 notes.)