A native of Washington, D.C., Greely studied interior decorating, various applied arts and crafts, and farming before earning certificates in both landscape architecture and architecture at the Cambridge School for Domestic Architecture and Landscape Architecture for Women in Cambridge, Massachusetts, in 1920. She worked as a draftsman for Fletcher Steele in Boston before returning to Washington to join the office of architect Horace Peaslee. In 1925 she became the first woman in Washington to be licensed as an architect. In her 40-year career, she designed more than 500 landscapes, specializing in residential design and focusing on the integration of house and garden. She worked primarily in Virginia, Washington, and Maryland, traveling further afield primarily to focus on the second homes of existing clients. In the 1940s and 1950s she also took on some larger-scale projects, including museums, embassies, schools, government housing projects, suburban developments, and the grounds of military installations. Because she insisted on the highest quality of workmanship, Greely’s well-built projects have enjoyed exceptional longevity.