Recent studies by economists exploring the nexus between culture and fertility have focused on cultural transmission from the origin country rather than the origin family. Our paper extends this avenue of research by investigating how family-specific 'cultural transmission' can affect fertility rates. In this context, we define 'culture' as referring to intra-family norms, and 'cultural transmission' refers to the transfer of these norms across generations within a family. We also allow for peer-group influences through the inclusion of controls for age cohorts and for non-English speaking country of birth. Following the methodology of Miranda (2005) and Machado and Santos Silva (2005), we estimate count data quantile regression models. Using unique data from the British Household Panel Survey, we find that a woman's origin-family size is positively associated with her own completed fertility in the destination family and that her country of birth also matters. The effect of origin family size increases as we move from the lower to the upper tail of the conditional fertility distribution. For a sub-sample of continuously partnered men and women, both partners' origin-family sizes significantly affect destination-family fertility. Our findings are robust to a number of specification checks.