The term vulnerability has little theoretical purchase in social policy. It is used widely as a short-hand phrase to describe deficit. As such it provides only limited value and has little regard for the wider structures of society that might ameliorate, sustain, or exacerbate vulnerability. There is, however, a critical literature that seeks to understand the social, economic and political relationships that produce vulnerability and its potential opposite, flourishing. This paper draws on this theoretical literature, focussing particularly on relational accounts of autonomy, capabilities and functioning, and the role of societal institutions. Using cases drawn from empirical research investigating how grandparents care for their grandchil...