Families are the primary source of care for children, a safety net for young adults, and the preferred source of care for older adults. In a context of increased longevity, family complexity, and economic inequality, transfers of resources within families have likely changed. This dissertation examines how grandparents, parents, and children exchange support in a context of family complexity and socioeconomic inequality. It relies on data from the Consumer Expenditure Survey (CEX) and on qualitative data collected through interviews with older adults in upstate New York. Chapter one examines whether and how coresidence with grandparents is associated with child-related investments. I find that living with grandparents represents an adaptive strategy that helps low-income or single parents invest more money in their children’s education, hobbies and activities, and to save on the costs of child care. Chapter two examines the supportive roles of adult step-children in the lives of older step-parents across social classes. Through this qualitative inquiry, I find that adult step-children represent important sources of actual and perceived support and that step-parents of different social classes engage in different strategies to establish and maintain supportive ties with step-kin. Specifically, the scarcity of lower-SES step-parents’ resources and the instability of their (and their children’s) social environments seem to promote a specific type of supportive tie – contingent ties, that allow lower-SES step-parents to conserve their resources and develop reciprocal and supportive relationships with some but not all of their step-children. Chapter three examines the effects of unconditional cash transfers on child-related consumption across social classes. It relies on the case of the Alaska Permanent Fund Dividend in order to determine whether and how lower and higher-SES parents invest “free money” in children differently. Findings from this study suggest that the average Alaskan household increases its levels of child-related consumption more than non-Alaskan households on the month in which they receive the Dividend payout. They also suggest that parents across socioeconomic classes make similar investment decisions when receiving unconditional cash-transfers in terms of the amount that they dedicate to children, but that higher-SES parents may be more likely to invest this additional financial resources in ways that promote cognitive and non-cognitive development of children. Collectively, this dissertation provides evidence that family structures, relationships, and socioeconomic context shape micro-level decisions regarding support exchanges shape, which may have important implications for the well-being of family members across the life course.