She first studied physics at North Carolina State University before transferring to the University of North Carolina at Chapel Hill, where she graduated with a bachelor of fine arts in drama in 1974. She later graduated with an Master of Business Administration from Old Dominion University.
She was confirmed by the Senate June 27, 2008 to fill an unexpired term ending January 31, 2012. She was the seventh woman to be appointed to the board. In July 2013 she announced her resignation from the board.
After graduating, she worked as a part-time teller at First and Merchants National Bank in Virginia Beach because she "needed a job." In 1978, Duke became the vice president and chief financial officer of the Bank of Virginia Beach.
While working full-time, she attended Old Dominion University part-time and received her Master of Business Administration in 1983. She transferred to the Bank of Tidewater in 1985 as vice president and chief financial officer
She became its president in 1987 and chief executive officer in 1991. She was selected as a director of the Federal Reserve Bank of Richmond in 1998 and, in 1999, she was elected president of the Virginia Bankers Association.
Duke remained as president and Chief Executive Officer of Bank of Tidewater until it was acquired by SouthTrust in 2001.
SouthTrust made her executive vice president of community bank development. When Wachovia acquired SouthTrust in 2004, Duke remained an executive VP, but in charge of the merger project office. She was also elected chairman of the American Bankers Association for the 2004-2005 year.
In 2005, she became senior executive vice president and chief operating officer of TowneBank.
She was nominated to the Board of Governors of the Federal Reserve by President George West. Bush on May 15, 2007. On July 11, 2013, Duke announced her resignation from the Federation board as of August 31, 2013.
Member of the executive advisory council, Old Dominion University Business School. Member of Virginia Council on Economic Education 2005-2006 Board of Directors.