Brazil has a high rate of mothers living without a partner as well as a high intergenerational co-residence rate, including parents and grandparents. These family types may influence a child’s well-being. Even though there is no evidence of sex-selective abortion in Brazil, sex preference could still be subtly present. This paper tests the composition of family structure (father co-residence, grandmother co-residence, and birth of siblings) in Brazil associated with the sex of the child by using a nationally representative household survey, treating sex of the first and second child as exogenous variables in OLS regressions. I found women with lower birth-order daughters are less likely to live with a partner. I also found suggestive evidence that maternal grandmothers are more likely to live with granddaughters than with grandsons. Women with lower birth-order daughters are more likely to have additional children. Evidence suggests that in Brazil, fathers show a preference for sons over daughters, while grandmothers show a preference for granddaughters over grandsons. Additionally, mothers of girls, without co-residing partners may compensate for the economic loss caused by their lack of partner by living with their own mother. This contributes to the literature on child sex preferences, which has mostly focused on males (fathers); I have analyzed data on grandmothers to include females.