I think he means that as he studied a large sample (as opposed to a “convenience sample”) he has covered a diverse number of familial situations among the lesbian folk and his findings are “robust” in the sense that they represent a broad spectrum rather than a few hand-picked picture-perfect lesbian families typically trotted forward in the sellout media.
wow! i am impressed that you were able to glean all of that from that sentence! thank you for the clarification...