She graduated from Wesleyan College in Macon, Georgia in 1896 as its first Dramatic Arts degree holder.
After earning sufficient credit, Lyndon received a Master of Arts degree on June 17, 1914 – four years before women were admitted to UGA as regular students.
Upon her graduation, Lyndon taught English at Athens High School.
When women were finally admitted as full students during the 1919–1920 school year, Mary Lyndon was nominated by UGA Chancellor David C. Barrow and then elected by the University Board of Trustees to the positions of Associate Professor of Education and Dean of Women.
[1] Lyndon taught classes in the Peabody School of Education, directed the Thalian Dramatic Club, helped organize the University chapter of the Phi Mu Sorority (the first sorority at UGA), and founded the Pioneer Club.