Margaret Riley Crann was born on 7 August 1923 in New Earswick in North Yorkshire, where her father Thomas Crann was a research chemist and her mother a teacher; she grew up as a Quaker.
After studying at the Mill Mount School in York, she read mathematics and then geography in Newnham College, Cambridge, and earned a master's degree from the University of Cambridge, beginning in 1941 and finishing in 1944.
She became a social worker in Birmingham for a year before taking a position as a mathematics teacher at Putney High School, a girls' school in London where she eventually became head of mathematics.
[4][3] He writes that they met at the Jesus Lane Friends Meeting House in Cambridge, in her third and his first year at Cambridge, and that they fell in love after she hit him with a celery stick for making a pun.
[5] She retired from Putney High School in 1985, and returned with her husband to Yorkshire.