Researchers have studied family language planning within bilingual family contexts but there is a dearth of studies that examine language planning of multilingual parents who raise their children in one of the world's lesser spoken languages. In this study I explore the ideologies and language planning of Luxembourgish mothers who are raising their children bilingually in Luxembourgish and English in Great Britain, where there is no Luxembourgish community to support them and where a monolingual discourse prevails. All mothers strongly identified with Luxembourgish, aimed at developing active bilingualism and recognised their role in ensuring exposure to Luxembourgish. However, five mothers choose a one-person-two-languages model which limits exposure to Luxembourgish. The article illustrates the extent to which the mothers' management of their own and of the children's language use is mediated by their ideologies, experiences of multilingualism and their interactions in a large monolingual setting. (Contains 1 table.)