She graduated at Bristol University and was awarded a Research Scholarship at Manchester. She transferred to the University of Durham in 1959 and became a lecturer at King's College, London in 1961. She was subsequently a university lecturer in NT at Oxford and Lady Margaret Professor at Cambridge. She was elected President of the Society for NT Studies in 1988. Her major works are Jesus and the Servant (1959), The Son of Man in Mark (1967), Mark (Black Commentaries, 1991), Not Ashamed of the Gospel (1994) and the Shaffer Lectures, The Signs of a Prophet (1997). Her textbook Studying the NT reflects her concern for instructing lay preachers and her expository interests. She gave the Peake Memorial Lecture in 1978 on 'The Bible and the Believer'. She married W. David Stacey in 1978.