MB ChB Manch 1954, DPH 1958.
Leeson was born in Preston on 13 November 1930. She was educated at Morecambe Grammar School and the University of Manchester and shortly after qualifying was appointed house surgeon at MRI. Leeson was assistant lecturer in social and preventive medicine at the University of Manchester, later being appointed senior lecturer in community medicine and district community physician to South Manchester Health District. Leeson later became director of public health for North Manchester Health Authority. She was a member of MMS and was president of the Society for Social Medicine. Leeson was also a fellow of the Faculty of Public Health Medicine.