The bulk of the money will go to establish education centres at three London sites: the new Tate Gallery of Modern Art in the former Bankside power station, the Natural History Museum and the British Museum.
Educational work in regional museums and galleries will also benefit to the tune of Pounds 1m.
Mrs Duffield, who has also donated money to the Royal Opera House, has named the centres after her father, Sir Charles Clore who built a retailing and property empire. Sir Charles is already commemorated by the Tate's Clore gallery which houses its collection of Turners.
Sir Claus Moser, chairman of the British Museum Development Trust, praised her "visionary philanthropy" which would help to create the new centre in the south side of the museum's Great Court, due to open in November 2000.
It will replace the museum's outdated lecture theatre and a small seminar room, currently used by schools. Despite this meagre offering, a quarter of a million schoolchildren visit the museum in organised groups a year, eating their packed lunches in the colonnade. However, thousands have to be turned away.
At Bankside, a similar grant will provide two workshops, a film room, a seminar room and an activity area for the Clore education centre when the gallery opens in 2000.
The Pounds 1m grant to the Natural History Museum will unify the existing schools' assembly area, the teachers' information and discovery centres and activity rooms. It will also give greater access to the museum's collections through the "Investigate" pages on its website. Grants of between Pounds 2,000 and Pounds 25,000 will support education work nationwide over five years.
The donation was greeted with delight, not only by the museum directors, but also by David Blunkett, the Education Secretary, and Chris Smith, the Culture Secretary. Mr Blunkett said the funding would "draw togther the heritage we have in this country and across the world and make it accessible to young people and adults in life-long learning, in a way not previously possible. " Museums will emerge as a "major educational force," said Mr Smith.