Gregory joined the Air Force in 1977. She was assigned to the 47th Flying Training Wing, the 3rd Tactical Fighter Wing, and to Pacific Air Forces before attending the Air Command and Staff College and the Industrial College of the Armed Forces. Later she served as Military Assistant to the United States Secretary of Defense during the 1993 Presidential Inauguration. After graduating from the Industrial College of the Armed Forces in 1994, she was assigned to work with the Joint Chiefs of Staff and became Chief of the Financial Analysis Division for Budge of the Pacific Air Forces in 1996. In 1999, she was named Director of Financial Management and Comptroller of Air Force Space Command before being assigned to the Office of the Assistant Secretary of the Air Force for Financial Management and Comptroller. Her retirement was effective as of September 1, 2006.