Anita May Gahn Keller lived in St. Louis, Missouri, until the age of thirteen, and then moved to Washington, D.C. She graduated from Sacred Heart Academy High School in 1941 and then studied drama and speech at Catholic University in Washington. She moved to Chicago, Illinois, with her family in 1942 and worked briefly for the Railroad Retirement Board.
Keller joined the Air Transport Command in 1942 as a civilian. She had training at Quantico, Virginia, and then began work in the Pentagon Annex as a cryptographer. In February 1943, she was transferred to the 36th Street Air Force Base in Miami, Florida, where she continued working as a cryptographer and also trained other in coding and decoding. In 1945, Keller transferred as a civilian to the Signal Corps and was relocated to Jefferson Barracks in St. Louis.
After the war ended, she organized counselors who processed men out of the military. She met Herbert Keller during this time and they were married in May 1947. Keller left the work force to raise their two children. Herbert Keller worked for National Cash Register, which took the family to Lexington, Kentucky, and then, in 1970, to Greensboro, North Carolina.