Community Health Workers (CHW) work in the public health sector in Brazil and are the central institutional actors in the socio-political changes taking place in the country. The CHW are responsible for public health monitoring in working class families, particularly for the mother-child relationship. These families do not conform to the nuclear family model, and maternity is lived out within a network of women helping each other. The CHW work as "police" among the women, seeking to construct a maternal role which has been transformed by public health, or "healthified," informed by empirical research in public health in areas like the reduction of infant mortality. However, the CHW work in the same neighborhood where they live, are themselves working class women and are part of these networks of child care. If they are to "police" the women, their methods of regulation are unusual. The CHW are "friends" of the women, and therefore are themselves regulated by the residents of the neighborhood. While other studies have reported on the paradoxical position of the CHW, they do not take into account the resulting conflicts and arrangements. This article aims to do this by showing how the Brazilian public health system is finding original methods for public health regulation in relationships between peers and friends among working class women.