Access to resources, both material and social, are central elements in responding to social and environmental transition, and adapting to change, yet the ways in which such access is negotiated within and across varying household structures is not well understood. In semi-arid Kenya, persistent drought has made male incomes from pastoralism insecure, and contributed to women's growing engagement with trade, farming and other independent enterprises, for survival. This has, however, raised questions about women's dependence on men for household provisioning, and enhanced expectations of reciprocity in both production and reproduction within households. While demographers note the rise in female headship in sub-Saharan Africa, and female headed households are often the target of policy attention, the situation on the ground is much more complex. Polygamy, separation and consensual unions, multi-generational and multi-locational households, point to a growing diversity in gender and generational relationships, in rights, responsibilities and norms. Based on data from household surveys, focus group discussions and life history interviews with differently positioned women and men within pastoralist communities in northern Kenya, the paper explores the implications of changing household structures beyond headship, in particular the loosening of marriage ties, frequent separation and regrouping, on relational vulnerability and the micro-politics of adaptation in the region.