Davies was born in Abadan, Iran, on 14 April 1933 where her father Stanworth Adey was working as an engineer at the Anglo-Iranian Oil Company, and the family later moved to New York.

One of five staff at the Institute of Contemporary Arts in Dover Street London, and one of 36 after it moved to The Mall, Davies experienced its period of anarchic management and overrun budget.

[8] Davies registered the business as a charity and found patrons and supporters in Magnum agency photographers such as David Hurn, and newspaper publishers Tom Hopkinson and David Astor, who with Roy Strong[9] (who in 1968 was encouraged by success in showing Cecil Beaton at the National Portrait Gallery)[10][11] assisted her in managing the first year expenses of £12,000 paid from the entry fees of 20,000 visitors, and further funding from the Arts Council covering a deficit of around £7,000.

She found the premises and put up the money, though she's not at all rich, and she persuaded distinguished men like Roy Strong from the National Portrait Gallery to sit on her board and got Tom Hopkinson, editor of the legendary Picture Post, as chairman.

International figures such as Arthur Tress and JH Lartigue, showed in the space, presented talks and workshops, and were offered accommodation in Davies' small flat at the top of 5 Great Newport Street as a way of encouraging their interaction with the Gallery patrons and attendance at parties that became legendary.

[14] Not all exhibitors met with approval of critics however, and in particular Davies' showings—three in as many years—of David Hamilton were condemned by Euan Duff for its "clichéd pictorial symbolism, exploiting soft focus, pastel colours, country landscapes and old houses, old fashioned clothes and even white doves to give a phoney impression of heaIth-food ad naturalness; they are a sort of wholemeal stoneground pornography," exhibited "because the gallery needs the money.

[22] The Gallery hosted the first British exhibitions by Irving Penn, J. H. Lartigue, André Kertesz, William Klein, Bert Hardy and George Rodger, and David Goldblatt's conscience-provoking images of apartheid in South Africa were presented by Davies in 1974, in his earliest solo show.

Equally she wanted to offer an environment to inspire, educate and inform audiences about the pivotal - and unique - role photography plays in our lives and communities.In 1991, Davies stepped down from The Photographers' Gallery when she found her time usurped by fund-raising needed due to changes to London boroughs contributions.

[25] She was replaced by Sue Grayson Ford, previously Director of the Serpentine Gallery,[13] and continued to be involved in photography as a visiting lecturer and curator as well as serving as Sculpture Coordinator for the 1984 Liverpool Garden Festival.