María Þorsteinsdóttir was born on January 7, 1862 in N. Þingeyjarsýsla. She died on June 30, 1933 in Minnesota.
Spouse: Pétur Vigfússon b. March 25, 1862 in N. Múlasýsla, d. in Minnesota on December 14, 1918. He is listed with the last name Peterson in the west.
Children: 1. Rósa (Rose) b. November 13, 1886 2. Gunnlaugur b. May 26, 1888; d. May 22, 1971 3. Pétur b. 1892; d. August 10, 1907. 4. Carl b. December 7, 1896. 5. Óskar b. April 23, 1899 6. John b. 1900; d. 1900 7. Árni b. April 15, 1901; d. October 6, 1962. 8. Lilja b. October 10, 1905.
Pétur came west with his mother, Halldóra Jónsdóttir, and his brother Gunnlaugur in 1876. They first lived in Lyon County, Minnesota, but Pétur later bought land in Lincoln County. María was daughter of Þorsteinn Sigurðsson and Guðný Ólafsdóttir.