After graduation, she worked from 1960 to 1963 at the Regional Virtus Laboratory, in
Ruchill Hospital, Glasgow as the
Sir Maurice Bloch Research Fellow in Virology. She was a lecturer (1963–1965) and senior lecturer (1965–1976) in
bacteriology at the University of Glasgow, and subsequently a
Reader in
virology (1976–78). She went on to become Professor of Bacteriology and William Teacher Lecturer (1978–88) at the university, and head of the Department of Bacteriology at
Glasgow Royal Infirmary. In 1988, Timbury was appointed director of the Central Public Health Laboratory of the
Public Health Laboratory Service, and she held that position until 1995. ==Selected works==