This paper discusses some of the issues surrounding the nature of adult play. More specifically, we explore "family play-learning", where play activities result in forms of added knowledge or insight for the adults involved. Adult play itself is an under-researched area, and play-learning even more so. We discuss related research and, in particular, the roles that adults adopt when the family is learning together through play. We focus in particular on the processes involved as adults learn with, and from, their children. While family learning is widely discussed, it--again in our view--lacks useful empirical evidence of its effectiveness. We use Bandura's theories of social cognition to analyse participant observations of 97 families while they made and played with toys within the informal educational system of a major science museum. Our agenda has been to detail some of the processes of learning through Bandura's four levels of observation, imitation, achievement and independence, and explore how these can be used to describe the "upward transmission" of knowledge from children to adults.