María Álvarez de Guillén (1889–1980), pen name Amari Zalvera,[Notes 1] was a Salvadoran businesswoman, writer and women's rights activist.

[17] She was one of the suffragists who won the right for the enfranchisement of women,[18] which was enshrined in the constitution developed by the Federal Republic of Central America.

Her book, La Hija de Casa (Daughter of the House) won second prize in the national literary competition Queremos[16][21] and was the first novel published by a woman in El Salvador.

[24] Not only did Álvarez work to compile the information, over the course of her ten-year service to the CIM, she frequently urged the government of El Salvador to amend the constitution to protect women's citizenship, so that upon marriage they did not lose their nationality and had equal civil rights to men.

[16] Her second published novel, Sobre el puente (Over the Bridge, 1947) wove a love story throughout a historical account of Panama's relationship with Colombia and the United States.