What happens when immigrant girls are given increased opportunities to integrate into the workplace and society, but their parents value more traditional cultural outcomes? We answer this question in the context of a reform which granted automatic birthright citizenship to eligible immigrant children born in Germany after 1 January 2000. Using survey data, we collected from students in 57 schools and comparing those born in the months before vs. after the reform, we find the introduction of birthright citizenship lowers measures of life satisfaction and self-esteem for immigrant girls by 0.32 and 0.25 standard deviations, respectively. This is especially true for Muslims, where parents are likely to prefer more traditional cultural outcomes than their daughters. Moreover, we find that Muslim girls granted birthright citizenship are less integrated into German society: they are both more socially isolated and less likely to self-identify as German. Exploring mechanisms for these unintended drops in well-being and assimilation, we find that immigrant Muslim parents invest less in their daughters’ schooling and that these daughters receive worse grades in school if they are born after the reform. Parents are also less likely to speak German with these daughters. Consistent with a rise in intra-family conflict, birthright citizenship results in disillusionment where immigrant Muslim girls believe their chances of achieving their educational goals are lower and the perceived odds of having to forgo a career for a family rise. In contrast, immigrant boys experience, if anything, an improvement in well-being, integration, and schooling outcomes. Taken together, the findings point towards immigrant girls being pushed by parents to conform to a role within traditional culture, whereas boys are allowed to take advantage of the opportunities that come with citizenship. To explain these findings, we construct a simple game-theoretic model which builds on Akerlof and Kranton (2000), where identity-concerned parents constrain their daughter’s choices, and hence lower their daughter’s well-being, when faced with the threat of integration. Alternative models can explain some of the findings in isolation.