Marion was born in New York and moved to California in 1926. Attended Keuka College in New York and Occidental College in California. Graduated college in 1929. Married Willis Tinling in 1933 and divorced in 1947. She raised her three children as a single mother. She worked as a research assistant and publications manager at the Huntington Library in San Marino for 19 years. Moved to Sacramento in 1949 and worked for the Dept. of Education as an editorial assistant. In 1954 she moved to Wash. DC. To work with the National Historical Publications Commission at the National Archives transcribing the original shorthand notes of the House of Representatives in the first Federal Congress of 1789-90. Later, as a Guggenheim Fellow, she spent a year in London researching the letters of Wm Byrd of Westover. During these years, Marion transcribed and edited several historical books of the Byrd family and is considered the definitive expert on William Byrd. In 1963 she returned to Sacramento and went to work with the Sacramento County Dept. of Social Welfare. It was at that time she established the first non-profit agency to deliver meals to the elderly, Meals a la Car. After retirement she continued as President of the Board for the agency. During her retirement, she wrote several books on women's history, all of which are used throughout the country in women's history classes. Her last book was published when she was 97.