She was nominated to the United States Naval Academy by her Congressman James Sensenbrenner and graduated with the Class of 1985[1] with a Bachelor of Science Degree.

After attending Navy Supply Corps School in Athens, Georgia, she was assigned to the USS Lexington homeported in Pensacola, FL.

At the end of her obligated active duty service, she transferred into the United States Navy Reserve and attended Stanford Graduate School of Business in Palo Alto, California.

Commander Dunning retired from the Navy Reserve in 2007 after 22 years of service as a commissioned officer in a ceremony on board the USS Hornet (CV12) in Alameda, California.

[6] On June 10, 1993, a three-member Navy administrative board recommended that she be honorably discharged despite arguments that the action violated a federal judge's ruling the previous winter.