The current study quantitatively applies Spolsky's triangular framework of language policy, including beliefs, practices, and management, to the family domain by investigating language policy in multilingual families in Belgium's Flemish Community. Firstly, we examine whether the three components in fact call for an independent description and examination. Secondly, we address the relationships between the components. To that end, we developed three scales for each of the language policy components according to Spolsky's model, and we tested construct validity of these scales using confirmatory factor analysis. Respondents were 776 multilingual families in Belgium. The results of our analyses confirmed that language policy in the family domain is not a unitary construct and that even though the three components are interconnected, they can still be described independently from each other. Interestingly, while beliefs and practices, and practices and management, were strongly correlated, a similar relationship was not found for beliefs and management, a finding which goes against what was reported previously in more formal domains of language policy. We believe that the current study opens up a wide range of follow-up investigations that dig deeper into the differing dynamics between language policy components in formal institutionalised domains, and the informal family sphere.