Born September 22, 1957, in Columbus, Georgia, Wagner received a Bachelor of Arts degree in English and history from the College of William and Mary in 1979.
After working as a short-order cook and waitress at a delicatessen in Williamsburg, Virginia, she began her career in the U.S. Army, serving eight years as a signals intelligence and electronic warfare officer, leaving active service as a captain in October 1987. That same year, she earned a Master of Science degree in systems management at the University of Southern California.
From February 1988 until May 1990, Wagner worked as an Army intelligence research specialist.
She joined Booz Allen Hamilton as an associate in May 1990,working in the areas of tactical exploitation of national capabilities, support to military operations, intelligence planning and intelligence systems architecture development.
In May 1993, she left Booz Allen to work on Capitol Hill as a staff member of the Program and Budget Authorization Sub-Committee of the House Permanent Select Committee on Intelligence.
Beginning in November 1995, she spent a year as staff director of the Subcommittee on Technical and Tactical Intelligence, also part of the House Permanent Select Committee on Intelligence. Her responsibilities included oversight of technical collection and processing capabilities in the National Intelligence Program and Military Intelligence Program.
From November 1996 to November 2000, Wagner worked for the Defense Intelligence Agency (DIA) as the director of the Military Intelligence Staff at the Pentagon. In this position, she conducted military intelligence community planning and was responsible for development and management of the General Defense Intelligence Program. She served as an associate member of the Military Intelligence Board (MIB) and oversaw the MIB secretariat. She also managed the implementation of the Joint Intelligence Virtual Architecture, a defense intelligence community-wide effort to modernize intelligence analysis and methods.
From November 2000 until April 2003, Wagner served as DIA deputy director for analysis and production at Boling Air Force Base. She was also the production functional manager, responsible for orchestrating analysis and production by analytic elements of the military services, the combatant commands other defense agencies.
For one year she served as the senior DIA representative to Europe and as liaison to the United States European Command (EUCOM) and to the North Atlantic Treaty Organization (NATO).
From May 2004 to April 2005, she was the executive director for intelligence community affairs at the CIA, making her responsible for the Community Management Staff, which provided strategic planning, policy formulation, resource planning, program assessment and budget oversight for the Intelligence Community.
Wagner then served from April 2005 through January 2007 in the Office of the Director of National Intelligence as an assistant deputy director of national intelligence for management and the first chief financial officer for the National Intelligence Program.
Wagner then took a position as an instructor in Intelligence Community management for The Intelligence and Security Academy, LLC, a private company that trains both members of both government agencies and private security firms. She also worked briefly as a substitute teacher in the Arlington County Public School system in Virginia.