Ms. Wendell was an entrepreneur, business manager, civic volunteer, mother of three, and grandmother of 10.
Born in 1925 in Winchester, Massachusetts, she graduated from Brimmer and May School in Boston and Smith College. In 1949 she married Harlan L.P. Wendell.
In 1975, while living in Wilmington, Delaware, she was hired to rescue and manage the Christiana-Millbrook Tennis Club. From a failing membership of 150, she rebuilt the club to 1,000 members. She then formed Tennis Management Services to provide consulting services in four states and managed Delaware's Junior Wightman Tennis Development Program.
In 1984, she developed an aluminum turkey lifter to help cooks lift the bird from a hot oven. After successful sales, she sold the product to Rowoco in Elmsford, New York, a large maker of kitchen specialties.
Moving to Detroit with her family, she launched a retail corporate sales and mail-order chocolate chip cookie business, named Conomo Cookies. She contracted production with a local bakery and sold more than 525,000 cookies in the first two years.
Ms. Wendell was a teacher at Brimmer and May School and at an Arlington, Massachusetts, public school. In Wilmington, she was a trustee of Brandywine College and president of the Delaware Smith College Club. She was active in many civic groups in Essex, Massachusetts. She is listed in "Who's Who of American Women."
She is survived by her husband, Harlan L.P. Wendell; children Harlan Wendell of Menlo Park and Thayer Adams of Woodside; and 10 grandchildren.