[2] In 1951, she was appointed assistant to R.A. Skelton, superintendent of the Map Room at the British Museum, succeeding him in 1967.
In 1968 she was responsible for the acquisition of the map collection of the Royal United Services Institution.
She also discovered the earliest version of England's first globe, by Emery Molyneux and thought to date from 1592, at Petworth House.
[citation needed] She was the chairman of the standing commission on the history of cartography of the International Cartographic Association.
[citation needed] Key publications include Carteret's voyage round the world, 1766–1769,[3] Cartographical innovations,[4] and the Historians' guide to early British maps.