Margareth is an active member of the Massachusetts Brazilian Immigrant community; she has been assisting green card holders with Citizenship applications, young students with Deferred Action for Childhood Arrivals (DACA) applications and promoting civil engagement.

In Framingham, she served as Town Meeting member, as Framingham Democratic Town Committee Treasurer, as a board secretary of the Brazilian American Center (BRACE). In 2019 she was appointed Commissioner for the MetroWest Commission on the Status of Women (MWCSW).

In 2016, Margareth co-founded the movement Brazilians for Political Education, which was created to help members of the Brazilian, and other communities, to learn how to be politically active and engaged. In 2017 she successfully runs for City Councilor in Framingham, MA becoming the first Brazilian American Citizen Women to be elected for a government position in the United States, serving for multiple terms. In 2023 Margareth was appointed Commissioner on the Governor’s Advisory Council on Latino Empowerment.