In 1935 she enrolled at Duke’s Women’s College where she met , a then medical student who eventually became the chief of Duke Hospital’s Division of Thoracic Surgery. Semans and Trent married in 1938 and together they had four daughters. The next year, Semans graduated from Duke, receiving a degree in Art History. However, just nine years later in 1948, Trent died of lymphoma, leaving Mary a widow with four girls. Pushed by her mother and with the support of her childhood governess, Semans went back to Duke University as a student for three more semesters. While back at Duke, she met James Hustead Semans, a urologic surgeon visiting from Atlanta. Five years later Mary remarried to James, who that year joined Duke’s medical faculty. Together they had three children.
He married Mary Parker, married 11 Dec 1678 in Chelmsford, MA. Mary was the daughter of Abraham, brother to James father Capt. James Parker. Mary and James were first cousins.