Despite a recognition of the importance of families in providing informal care to frail seniors, there is no consensus as to who constitutes the caregiving family. The authors discuss the current ideology about the caregiving family and the state of knowledge about its composition and propose that the caregiving family has actual and potential elements. Based on the assumption that the concept of “who's the family” is socially constructed, the authors argue that it is essential to understand “who's the family” from the perspective of primary caregivers in order to evaluate the nature of family support. This paper challenges the notion that the cargiving family is equivalent to the kin family. It is argued that the status quo in which a simplistic view of family caregiving is used to justify pressure on families to provide more care is not sustainable.