Fellows was born the daughter of a Methodist minister and the younger sister to writer Annie Fellows Johnston in Evansville, though they soon moved to McCutchanville where she grew up. After graduating from Evansville High School, Fellows worked as a secretary and court reporter. She then toured Europe with her sister before marrying Hilary Bacon, a local banker and merchant, in 1888. Over the next few years she settled into a lifestyle of middle-class domesticity, having several children and later in 1897 publishing Songs Ysame, a volume of verse with her sister. However she would soon be afflicted with an illness that lasted several years, which may have had an affect, if only perceived, on her later creativity. She one day almost by chance came upon the riverfront slums in Evansville, and soon became a "friendly visitor" for the local associated charities. Before long she was able to find an outlet in these voluntary and welfare campaigns, organizing the Men's Circle of Friendly Visitors, the Flower Mission for poor working girls, an Anti-Tuberculosis League, a Working Girls' Association, and the Monday Night Club of influential citizens interested in charitable work. She soon determined substandard housing to be the main cause of social problems, and would attempt to have regulation on tenements added to new city building codes, but was unsuccessful. By 1908, Fellows decided to approach the issue from a higher level of government, and drafted a model state law. After a year of directing the promotion and campaigning of the bill, it was finally passed by the Indiana legislature in 1909. Amendments would soon weaken the bill's effectiveness in Evansville and Indianapolis, so by 1911 Fellows helped to organize the Indiana Housing Association. Within two years the association had successfully pushed through a bill of statewide application. She published a book in 1914, Beauty for Ashes, which recorded her campaign. She later played a large part in the passing of a law in 1917 which allowed for the condemning of unsafe and unsanitary dwellings. She remained active through her later years, serving as head of the executive committee of the Indiana Child Welfare Association, as well as with the state Commission on Child Welfare, where she continued to work to pass child labor and school attendance laws and establish a juvenile probation system.