This article discusses family language policy and the tensions between mothers' and children's language beliefs in two Vietnamese immigrant families in Melbourne. These tensions have frequently been discussed from the parental perspective, but it is less common to include the children's voice. We draw on a larger in-depth qualitative study of family language policy in Vietnamese families living in Australia to explore the language beliefs of both children and adults. Employing Fitzsimmons-Doolan's [2018. "Language Ideology Change Over Time: Lessons for Language Policy in the U.S. State of Arizona and Beyond." "TESOL Quarterly" 52 (1): 34-61. doi:10.1002/tesq.371] notions of pro-multilingual and pro-monolingual ideologies and Bourdieu's [1986. "The Forms of Capital." In "Handbook of Theory and Research for the Sociology of Education", edited by J. G. Richardson, 241-258. Greenwood Press] concept of capital, we explore family language policy from the perspectives of both children and their mothers, and show how these perspectives are associated with each other. Findings reveal the pro-monolingual stance of the children in opposition to the pro-multilingual stance of their mothers where the children and their mothers appeared to attach different degrees of value to English and Vietnamese. The findings reinforce the complexities in realising family language policy across languages.