Gender, migration status, and (parents’) country of origin are strongly associated with women’s labour force participation. Women tend to participate less than men; but in addition, first and second-generation minority group women have, on average, lower participation rates than third generation or higher, although there is significant variation across groups. Using data from Understanding Society, this paper tests whether women’s decisions to participate in the labour force affect the labour market behaviour of the following generation. Unlike women’s own mothers, the attitudes and behaviours of mothers-in-law are not expected to have any direct impact on the attitudes of their daughters-in-law that developed during the childhood. However, mothers’ behaviour may influence the next generation of women, independently of its impact on her own daughters and their attitudes, through the direct impact on her son’s attitudes and behaviour. This paper tests whether the work status of a woman’s mother-in-law during her husband’s childhood provides additional explanation over and above individual and couple-level factors of the probability of her labour force participation. Estimates from treatment effect models show that, ceteris paribus, having a working mother-in-law increased a woman’s labour market participation by six percentage points. Women from all minority groups, except Irish and Jamaican, were less likely than white majority to have a working mother-in-law. However, among those with a working mother-in-law, immigrant women were more likely to participate in the labour market than their UK born counterparts across all ethnic origin groups. Among those without a working mother-in-law, Pakistani and Bangladeshi women were less likely to participate, and Jamaican and African women more likely to do so.