Spending her childhood in Kingscourt, Co. Cavan until the death of her mother in 1953, after which she lived with her Godmother Cousin and her husband just outside Drogheda, where she continued her schooling. She joined Guinness at St. James’s Gate on 3rd May 1960, fifteen years to the day from her first day at Primary School in 1945. While working, Marion studied for a B.A. in History & English, (followed by a H.dip in Ed.) graduating in 1973. Ten years later, having studied for a B.L., she was called to the Irish Bar, but continued as Share Registrar at Guinness PLC until taking early retirement in October 1996. She has lived in Donnybrook in Dublin for the greater part of her life.