She was the first woman named a field demonstration agent by the United States Department of Agriculture, and later occupied high-level positions supporting the New Deal.

[1] Agnew began her education in local schools in Nottoway County before studying stenography at Smithdeal Business College in Richmond.

[1] The following year she migrated to South Africa, where she had accepted a position teaching business and working as a secretary in Paarl, at the Huguenot Seminary.

[2] Agnew continued her professional life upon her return from Africa; she worked as a teacher in Virginia, an office manager in New York, and general secretary of a number of Young Women's Christian Association chapters.

[2] She returned to Virginia to begin a system of professional training for rural girls; supported by the state superintendent of education, Joseph D. Eggleston, and agriculturist Seaman A. Knapp, she began implementing her ideas in 1910 in Nansemond[2] and Halifax Counties with the creation of tomato and canning clubs.

[2] After ten years in the position she left to work for the YWCA's national board, as a member of the finance department,[1] in which role she traveled the country raising money and developing plans to fund local YWCM chapters.