Nellie Mae and her twin sister were born in Serena Township, LaSalle County, Illinois on November 18, 1875. They were the second and third children of Daniel Dondanville and Mary Ellen DeBolt. She moved with her family to Sheridan, Illinois when they sold their farm in the late 1890s.
Nell moved with her parents to Montana In 1911 and took up a homestead adjacent to theirs at Lonepine on the Flathead Indian Reservation. During the period 1914 -16 Nell worked at the Twin Bridges Childrens Home, north east of Dillon. Her brother-in-law, Jack Bras, was with the telephone company in Twin Bridges at that time and may have been instrumental in Nell's obtaining that position. She later worked at the Hutton Home in Spokane.
She eventually returned to Lonepine and lived with her parents. Following their deaths,in the early 1930s, she opened their home to school teachers in need of a place to live. Nell was a member of the Hot Springs Women's Club, Nyah Grange, and was one of the early members of the Lonepine Ladies Community Club.
Faced with failing health due in part to her weight, Nell returned to Ottawa, Illinois where she could be under the care of her brother-in-law Dr. William P. Fread in in 1944. Showing some recovery she assisted with the care of her twin sister El when she became ill in the early 1950s. Following her sister's death in 1952, she continued to keep house for Dr. Fread until the failing health of both necessitated Nell's placement in Highland Nursing Home in Ottawa.
Following the death of Dr. Fread in 1964, Nell returned to Montana. She spent the last two years of her life in Hot Springs Manor, near the homes of her sisters Lyda and Elizabeth and her brother Vern. Nell died on January 2, 1967. She was buried in Murray Memorial Cemetery in Lonepine.