Despite a widespread assumption that the nuclear family is normative, the family takes a number of different forms cross-culturally. In this talk, I’ll present evidence which suggests that help from family members beyond the married couple is required for raising children. I’ll then go on to consider how such help from family influences women’s fertility. The data used in this talk will be largely secondary data, but the sources are varied, from large-scale nationally representative datasets, through longitudinal demographic surveillance sites in lower income contexts, to data from small-scale societies collected by anthropologists. The conclusions of this talk are that the extended family has an important influence on demographic outcomes such as child mortality and female fertility, though how this influence plays out varies in different cultural and economic settings.