Mariann attended Duke University, graduating summa cum laude with a mathematics major and winning the Anne Flexner creative writing award. On a Woodrow Wilson Fellowship, she went on to graduate school in English at Yale University, specializing in Renaissance literature. She works at Fairfield University in Connecticut as a Professor of English, teaching courses in allegory, poetry, women's studies, and gender studies. Her book of literary interpretation, Love Words, was published by Cornell University Press.

In Fairfield, she has sung with local chamber groups and has performed as a classical soprano soloist. Her two sisters, Catherine Andrews and LB Sanders, are now physicians in Atlanta and Boston. Her son Tim teaches Tai Chi, and her daughter Jennifer is a classical flutist. She and her husband Richard, who teaches Shakespeare, live in Fairfield, Connecticut.