This article reports the results of a social network analysis (SNA) performed on the mother's primary network of interaction in 15 Mexican American families in the city of El Paso, Texas, the neighbourhood of La Villita, in Chicago, and the city of Lincoln, Nebraska. The goal of this study was to examine potential opportunities for Spanish use by her children as well as sources of information and influence that might shape her views about the benefits and drawbacks of linguistic maintenance in her family. The network features of "primary language of exchange," "density," "strength of ties," "level of integration to local, regional and transnational networks" and "gender segregation" were examined. Results suggest that in these families Spanish transmission is influenced by mother's perception of benefit/cost, mother's participation in networks where Spanish is vested with social capital, and mother's linguistic competence. (Contains 1 table and 5 notes.)