Mildred Inks Davidson Dalrymple was born on 14 February 1920 in Llano, Texas, where her father was the mayor. Her father died when she was fifteen, and the family moved to Austin, Texas. Dalrymple graduated from Llano High School and then attended the Texas State College for Women, where she majored in journalism.
Dalrymple began working as a civil service typist on military bases in San Antonio, Texas, when World War II started. In June 1942, she married Bill Davidson. He was killed several months later while flying B-17s in Europe. Dalrymple then joined the Women Airforce Service Pilots (WASP) and graduated from training at Avenger Field in Sweetwater, Texas, in May 1944. She was stationed at Maxwell Air Force Base in Montgomery, Alabama, until the WASP disbanded in December 1944.
Dalrymple worked for the legislature in Washington, D.C., after leaving the WASP. She married Edwin Dalrymple in 1946 and after a brief stay in Newark, New Jersey, the couple settled in Washington, D.C.