Joanna originally qualified and practised as a solicitor in the City of London. After a period teaching Law at New Hall (now Murray Edwards College), Cambridge, she has spent her working life in college and university financial administration, including ten years as Treasurer of the University of Cambridge. She is an Emeritus Fellow of Murray Edwards College and of Clare Hall, University of Cambridge. She is a Trustee of a range of charities, including a children's choir and a Trust managing sheltered accommodation and a care home in Cambridge. She is on the Audit Committee of Cambridge University Press and Chairs the Cambridge Building Society Retirement Plan.