Socioeconomic inequalities in health and well-being are large, beginning early in childhood and accumulating over the life course, but they also vary widely across rich developed nations. Despite this well-known cross-national variation, research has yet to examine why children's health disparities might be larger or smaller based on national policy contexts and macroeconomic conditions. Parental health and well-being suffer under high work-family or economic strain, which may directly impact children's health inequalities by family social class. These childhood health disadvantages, if not substantially improved, compound to even larger adult inequalities. To examine the role of national work-family reconciliation in children's health, we merge country-level policy data with 2006 and 2010 World Health Organization child-level data on mental and physical well-being and family economic disadvantage. Based on adjusted estimates, we find greatly narrowed disparities in children's self-rated health as work flexibility and vacation-sick leave mandates become more generous. However, cash transfer policies including family benefits spending and childcare costs were not associated with the size of children's health disparities. Taken together, our results suggest the distinctive value of better work-family accommodations, rather than any generic cash allowances, for lessening family-based inequalities in children's health and human capital development.