Marianne was born in New Portland, Maine, on December 31, 1925. She was the sixth child (of seven) born to Cephas and Josephine (Williamson) Walker. Tragically, when Marianne was seven years old, due in large part to financial stresses during the Great Depression, the family broke up and homes needed to be found for the children. Marianne was adopted by Carroll and Annie (Bibber) Douglass of East Auburn, Maine. They lived on a small farm, and Marianne attended the one-room school where Annie taught. Marianne had a gift for music, which her stepmother encouraged, and after high school she went on to the Boston University School of Music where she majored in voice. It was there that Marianne met her future husband, Robert Corley. Marianne and Bob married on August 28, 1948, and had three children.

Marianne and Bob settled in the Boston area where Bob became an accomplished musician and music teacher. Marianne devoted herself to raising their three children and also worked at times as a bookkeeper and as a real estate agent. Marianne sang as a soloist at several churches and was a member of the Lexington Choral Society. Notably, she played a lead role in a production of Gilbert and Sullivan's The Pirates of Penzance put on by the Society.

After retirement Marianne and Bob enjoyed their home in Zephyrhills, Florida, as well as maintaining residences in Maine. They enjoyed travelling together and went on excursions across the United States and in Europe. Marianne also became a skilled quilter.

Marianne is survived by her daughter Robin (Tom) Brown, of New Braunfels, Texas, her son Scott (Kathleen O'Grady), of Saskatoon, Saskatchewan, her five grandchildren and her great-grandchild. She is predeceased by her husband Bob and son Tom.

Marianne will be laid to rest next to her husband Bob at Pleasant View Cemetery in Orleans, Vermont. A private interment service will be held for immediate family.

In lieu of flowers, the family is requesting that donations be made to Beacon Hospice, an Amedisys Company. Checks can be made payable to Amedisys Foundation and mailed to Amedisys, ATTN: Amedisys Foundation, 3854 American Way, Suite A, Baton Rouge, LA 70816.