De Betancourt was born sometime in 1703, probably on the Island of Lanzarote, the easternmost island in the archipelago.
There she married Juan Rodriguez Granado. They would have five children: Pedro, Josepha Rita, Paula, Manuel and Juan de Acuña. The last child was born upon the immigrants’ arrival in Vera Cruz and after De Betancourt’s husband’s death from fevers. Under Spanish law, Granado’s widow retained the title to his property and became the head of the family. A census conducted by the Spanish authorities described Maria de Betancourt as slender, with a good figure, a long face, a fair complexion, black hair and eyebrows, and a thin nose.
Within a few years de Betancourt married her second husband, Martin Lorenzo de Armas, producing four more heirs: Basilio Lorenzo, Antonio, Joseph and Fermin. De Betancourt and her husband prospered. She operated three ranches, including Rancho de San Antonio del Cibolo. From there she provided beeves and other supplies to the forces of Bernardo de Galvez, Governor of Spanish Louisiana, who was supporting the American Revolution by fighting the British in Louisiana and Alabama. The cattle were driven from the San Antonio de Bexar area, up the La Bahia Trail, across Texas and the Sabine River into Louisiana.
Maria Robaina de Betancourt was prominent in the social life of San Antonio. Her elegant, well-furnished home was located in the center of the city. She died January 26, 1799, at the age of 96. Her name is inscribed on the Texas DAR Patriot Monument in the Texas State Cemetery, Austin, Texas.