Mary was born April 14, 1926, in Sedalia, Mo., the daughter of Fred and Louise (Wallis) Bruns. She graduated from Warrensburg High School in 1944 and was united in marriage to Donald Douglas Isaac on June 29, 1946, in Warrensburg.

She was employed at United Telephone Company until their first daughter, Denise, was born. After her second daughter, Phyllis, started kindergarten, she began working at Swisher Mower & Machine Company where she retired after 37 years.
She was a member of the Lutheran church since an early age. She was a member of the American Legion Auxiliary for 63 years, including serving as president and district president. She also served as president for the AARP and was active in Merry Widows and the Red Hatters.

She is survived by a brother, Leonard, and wife Ada Bruns of California; two daughters, Denise, and husband Russ Crim of Warrensburg; and Phyllis and husband Donnie Hitaffer of La Monte, Mo.; granddaughter, Kelly and husband Justin Trauschke of Grain Valley, Mo.; granddaughter, Breana Eoff of Springfield, Mo.; grandson, Billy Crim of Warrensburg; grandson, Drew Kerr of St John, Va.; great-grandsons, Jake and Nick Frede and Aiden Eoff; and great-granddaughter, Delaney Trauschke.

She was preceded in death by her husband, Don; brothers, Leo and Raymond; and her parents, Fred and Louise Bruns.