Nancy Margaret Christ was born in North Brunswick, New Jersey. After graduating from high school there in 1949, she attended Ann May School of Nursing in Neptune, New Jersey. After completing the program in 1952, she briefly remained at Fitkin Hospital as an operating room nurse before moving with friends to Miami Beach, Florida, in 1953. In 1954 she returned to New Jersey to work at Muhlenberg Hospital in Plainfield. She later worked at Columbia Presbyterian Hospital while attending Teachers College at Columbia University to earn her bachelor's degree in nursing.
Christ joined the United States Army Nurse Corps in 1961 in order to help pay for her last year of tuition. After finishing her degree in 1962, Christ was stationed at Letterman Army Hospital in San Francisco, California. During the Cuban missile crisis that fall, Christ was deployed to Miami, Florida. She was next stationed at West Point, where she cared for cadets, and then was transferred to UCSF Medical Center for graduate study. At that point, Christ's twin sister joined the Army Nurse Corps as well and requested duty at Letterman Army Hospital.
Christ served in the 3rd Field Hospital at Tan Son Nhut Air Base in Vietnam for a year, beginning in February 1966. While there, Christ worked alongside her twin, and earned the Bronze Star for exemplary service. After her return from Vietnam in 1967, Christ worked as an army recruiter until 1969, when she returned to duty as a practicing army nurse. Christ retired from the army as a lieutenant colonel in 1981.