This study is about some reflections on a broader ethnographic study on the motherhood of adolescent mothers while deprived of their liberty in the capital of Brazil. The juvenile justice system in Brazil imposes on these girls the fulfillment of a socio-educational measure of internment, in order to hold them accountable for committing an infraction. We sought to understand, in the first instance, what the political-institutional actions of this the political, social and moral discourses imposed on these young mothers. It should be remembered that these maternities fall into what we call the analytical category of “non-hegemonic maternities”. As a result of a network of involvement with motherhood predominantly made up of women - the "girl-mothers" and the institution's employees, this research sought to find out how the transversality of the social life of care and youth accountability expresses the different guidelines and representations about the social reproduction of adolescents in socio-educational detention, whose multiple moralities and regulations oppose the figure of mothers “in the measure”.