María studied theology, biblical studies, anthropology and social issues. At the age of 19, she joined a convent. In 1976, she arrived in Chapas as a missionary of the Eucharistic Franciscan Missionaries. Three years later she decided to leave the congregation. As a member of pastoral teams, she started to discover the situation of native people of Mexico, she supported local communities, in particular women, in learning and understanding their rights and socio-political situation. In 1992, she launched an initiative connecting all women’s groups from the San Cristóbal diocese to create space for joint organisation, freedom, and raising awareness of patriarchal relations. Since 1993 she is the member of the operational team, and since 2012, the coordinator and legal representative of DESMI A.C., a social organisation dealing with socio-economic development of native Mexicans in harmony with Mother Earth and principles of economic solidarity. On the invitation of the Human Rights Center Fray Bartolomé de Las Casas, she participated in the Permanent Court of Nations as the witness for the condemnation of impunity in the face of violence perpetrated by guerrilla groups and paramilitary organisations.
In May 2014, she was nominated by IDEX (currently Thousand Currents) to the Global Exchange HUMAN RIGHTS AWARDS.