As welfare-to-work reforms increase women's labor market attachment, the lives of their young children are likely to change. This note draws on a random-assignment experiment in Connecticut to ask whether mothers' rising employment levels and program participation are associated with changes in young children's early learning and cognitive growth. Children of mothers who entered Connecticut's Jobs First program, an initiative with strict 21-month time limits and work incentives, displayed moderate advantages in their early learning, compared with those in a control group. A number of potential mechanisms for this effect are explored, including maternal employment and income, home environment, and child care. Mothers in the new welfare program are more likely to be employed, have higher income, are less likely to be married, have more children's books in their home, and take their children to libraries and museums more frequently. However, these effects explain little of the observed gain in child outcomes. Other parenting practices and the home's social environment do explain early learning, but these remained unaffected by welfare reform. (Contains 1 figure, 2 tables and 3 footnotes.)