Within multilingual families, the emotionality of languages can impact individual and family wellbeing. But few studies have investigated the influence of the familial linguistic context in shaping emotional language use preferences. Guided by the Family Language Policy framework, we consider how the language use and the language attitudes of parents, siblings and children themselves affect the emotional language use preferences of children, independent of children's proficiencies in their heritage (HL) and institutional (IL) languages. We analyze unique data from over 500 primary school children (aged 10-12) from Moroccan, Turkish, Eastern-European and mixed descent living in Antwerp, the largest Dutch-speaking city of Belgium. We find that children's emotional preferences are strongly affected by their proficiency in the heritage language but not their proficiency in Dutch, by their parents' and siblings' language practices but not their own practice and by children's attitudes about the relative importance of HL and IL. Overall, the results suggest that emotional language preferences of children reflect children's own acculturation process as well as that of their families.