Why do conservative middle-income economies often fail to move women into modern sectors while urbanizing and industrializing? We ask whether cultural constraints are a development bottleneck that limits women's entry into tradable manufacturing and slows fertility decline and human-capital accumulation. We exploit the 1989 forced migration of ethnic Turks from Bulgaria to Turkiye. Refugee women shared language, religion, and ethnicity with native women but had much stronger labor market attachment and much higher manufacturing employment. We combine difference-in-differences with an instrument based on where the state settled earlier ethnic Turkish migrants through housing and land programs. Greater exposure to refugee women raised native women's labor force participation and employment a decade later, especially in male-dominated tradable manufacturing. Native men saw no significant gains. A one-percentage-point increase in the refugee-to-native ratio raises native women's manufacturing employment by 0.9 percentage points, roughly 23 percent of the 1990 baseline. Exposure also reduced fertility and raised middle-school completion among native girls and boys. These results suggest that an exogenous cultural shock relaxed a binding constraint on women's entry into the modern sector, a margin central to structural transformation and demographic transition. Evidence from intermarriage and the World Values Survey is consistent with this interpretation.