Duffield was educated at St. Mary's Grammar School for Girls in
Northwood Hills, now merged into
Haydon School, and
Exeter University where she graduated in 1975. She worked in the
DHSS 1976–85, then studied at the
École nationale d'administration in Paris 1985–86 and joined the
Foreign and Commonwealth Office (FCO) in 1987. She was posted to Moscow 1989–92, and was deputy
High Commissioner at
Ottawa 1995–99. She was High Commissioner to Sri Lanka, and
concurrently High Commissioner to the Maldives, 1999–2002. She returned to the FCO as director of the Wider Europe department 2002–04, then served as ambassador to the Czech Republic 2004–09. She was appointed chief executive of the
Westminster Foundation for Democracy (a body sponsored by the FCO) 2009–14. Duffield was appointed
CMG in the
2002 New Year Honours. ==References==