Mary Haynsworth Mathews was born in 1916 and grew up in Greenville, South Carolina. After graduating from Greenville High School, she attended Winthrop College in Rock Hill, South Carolina, for three years and then graduated from the University of North Carolina at Chapel Hill in 1937. After participating in the first production of The Lost Colony, she went to England to study with Russian director Michael Chekov, but returned to the U.S. in late 1938 when the school was moved to Connecticut. She remained with the group, performing around the country, until they broke up in 1942. She returned home to Greenville and joined the American Red Cross in 1943.
After two weeks of training in Washington, DC, Mathews sailed to England on the RMS Queen Mary. She was assigned to a Red Cross club in Essex, England, and then promoted to a club in Norwich, England, but then transferred back to a base in Essex in the summer of 1944. Mathews later went to Paris with the 386th Bomb Group, and then was moved to Le Havre, France, in April 1945. She was next stationed in Fulda, Germany, with a clubmobile, until she left the Red Cross in March 1946.
When she returned home, she continued to work in theater. Mathews participated in a touring Broadway show where she met fellow actor George Mathews, whom she married in 1951. Following a brief stint organizing recreation on United Fruit Company cruises, Mathews moved to New York and returned to the stage working in summer theater productions and TV bit roles. In 1974 the couple moved to Greenville County, SC.