Jan was born and raised in New Zealand. She came to Cambridge in 1970 to do her Ph.D. and then worked in Taiwan for over twenty years in an international agricultural centre. Together with colleagues from Asian countries she worked on improved technologies suitable for small-scale farmers with low incomes, work that was made available without charge to developing countries. Among other things, she edited the centre's newsletter and ran their website. She retired in 2004 and returned to Cambridge with her husband. She writes short stories and poetry.