Following her graduation from Westfield, Webster began work at the
British Museum, serving from 1964 to 1969 as assistant keeper of the Department of British and Medieval Antiquities. In 1969 the department was split in two and Webster moved to the newly-structured Department of Medieval and Later Antiquities (in 2000 renamed the Department of Medieval and Modern Europe), serving as assistant keeper until 1985, from then until 2002 as deputy keeper, and during 2002–2003 as the acting keeper. The departments were merged back into one body in 2002, the Department of Prehistory and Europe, of which Webster served as Keeper from 2003 until her 2007 retirement. During her time at the British Museum, Webster was the co-curator for four major exhibitions about the
Early Middle Ages. As part of the
Transformation of the Roman World AD 400–900 project of the
European Science Foundation, she also coordinated exhibitions in five major European museums. Webster's work, both before and after retirement, has also included the publication of works on
Anglo-Saxon art and archaeology. These include
The Golden Age of Anglo-Saxon Art, 966-1066 (1984),
The Making of England: Anglo-Saxon Art and Culture AD 600–900 (1991,
The Transformation of the Roman World AD 400–900 (1997),
Anglo-Saxon Art: A New History (2012), and
The Franks Casket (2012). She is the co-author of a forthcoming work on the finds from the
Staffordshire Hoard. ==Other activities==