This study examines time with children among women who remain childless in young to middle adulthood. The authors identify biologically childless women aged 25 to 44 years in the June 2004-2008 Current Population Survey, and use their subsequent time use diaries in the 2004-2009 American Time Use Survey to measure their time with children. The authors pay particular attention to time with children who are not one's "own" (by adoption or marriage) and to differences across educational groups of childless women. It is found that childless women frequently spend time with children, and childless women with no 4-year college degree are almost twice as likely to spend time with children as childless women with a 4-year degree. The authors also show how educational differences in childless women's time with children are mediated by work patterns, residential arrangements, and especially union status. The findings suggest large class differences in how women experience the boundary between childlessness and parenthood. (Contains 5 tables, 2 figures, and 1 note.)