There was one guy who did our nonprofit work full time - and he, Peter Schweitzer - still runs the organization, though he lives back in TN now. And his wife was in nursing school at the time. The two of them were the ones who came up with the idea to start the bilingual clinic that still operates in DC. (But I got the initial seed money from a Quaker charity that my uncle was involved with in Philadelphia. )
You are right there were 5-6 of us who worked construction/remodeling company that paid most of the bills. There was one woman who home-schooled the kids in the house, one woman who managed the kitchen and another who worked mainly with the nonprofit on our no-nukes work and another who worked as a kind of office assistant. So that is 12 adults, on average - it varied a little from year to year.
The rest were kids. Sometimes there were as many as 17 of them there. That is one difference with us and some other groups - we had loads of kids. And usually we had visitors staying with us who were there for various reasons. But anyway that was how I came up with the 30 number. We lived in a ten bedroom house that had other rooms too. It was a busy place.