Upon graduation she worked briefly at Chase National Bank in New York City before joining the staff of Antiques, where in 1930 she became secretary to Homer Eaton Keyes.
Winchester became an influential voice in the world of antique collecting, publishing scholarship by such historians and curators as Joseph Downs, Charles F. Montgomery, Marshall B. Davison, Irving W. Lyon, and Helen Comstock.
In the field of folk art, she published work by Mabel M. Swan, Esther Stevens Brazer, E. Alfred Jones, Carl W. Dreppard, Jean Lipman, and Nina Fletcher Little, among others.
[2] During her career she received the Smith College Medal in 1968 and the Henry Francis du Pont Award for the Decorative Arts from the Winterthur Museum in 1990.
[1] An oral history interview with Winchester, conducted between 1993 and 1995, is held by the Archives of American Art at the Smithsonian Institution.