Marguerite Clodfelter was born in Alberta, Canada, but moved to upstate New York at the age of ten. She attended Belleville Academy and then moved to Watertown, New York, and graduated from a school in Adams, New York.
Clodfelter enrolled in the Cadet Nurse Corps in 1944. She spent an academic year taking classes at Plattsburgh State Teachers College in Plattsburgh, New York, and then went to the House of the Good Samaritan in Watertown, New York, for clinical training. She served there for the remainder of the war, and was certified as a registered nurse.
Following the end of World War II, Clodfelter ended her affiliation with the Cadet Nurse Corps. She married Bob Clodfelter in June 1947 and moved to North Carolina, where she nursed at Watts Hospital in Durham while her husband attended law school at Duke University. She also worked briefly in a country hospital in Whiteville, North Carolina. Clodfelter has been an member of the League of Women Voters, the board of the Winston-Salem YWCA, and is a supporter of environmentalist causes.