This paper analyzes the work developed with a group of Latina mothers in a mathematics afterschool program for a period of 3 ½ years. The analysis of the productive patterns of interaction of this group of mothers with a group of bilingual participants shows that the program's participation and activity structure closely determines the quality of the mothers' participation. We present a sequence of attempts developed to alter this structure in order to successfully capitalize on mothers' leadership roles and knowledge during intergenerational and bilingual mathematical activity. We further discuss key social processes--acknowledging mothers as facilitators, focusing on communication rather than on a specific language, and supporting mathematics performance through social interactions--that opened up a space for Latina mothers' leadership and dynamic participation during bilingual mathematical activity.