Mary Haynsworth Mathews was born in Greenville, South Carolina, in 1916. She graduated from Greenville High School and attended Winthrop College in Rock Hill, South Carolina, before transferring in 1935 to the University of North Carolina in Chapel Hill. Mathews finished her degree in 1937 and joined Michael Checkov's theater group in Dartington Hall, England, in the spring of 1938. Mathews moved with the training group to Connecticut in December 1938 and toured across the United States with them for the next five years.

Mathews returned to Greenville in late 1942 and joined the American Red Cross in mid-1943. After two weeks of training in Washington, D.C., she was sent to work in a service club outside of London, England, near Essex. Two months laster she was sent to an air base in Norwich, England, where she remained through the summer of 1944. After another brief stint near Essex, Mathews transferred to an air base outside of Paris. In the spring of 1945, she was sent to a Clubmobile in Le Havre, France, and by August 1945 Mathews was stationed in Fulda, Germany. She remained in Fulda until March 1946.

Mathews returned to Greenville when she left the service and continued to work in the theater and for the United Fruit Company. She got married in 1951 and lived with her husband in New York until 1974 when they moved to Cedar Mountain, North Carolina.