She graduated from Bryn Mawr College in 1890 and took up a career in teaching, for a time, before giving it up to pursue studies in art with Heinrich Knirr in Germany and with Henry B. Snell in the U.S.[2] During World War I, MacIntosh was field secretary for the Pennsylvania branch of the Woman's Land Army of America.
[4] In that role, she traveled around the state engaging women in agriculture to boost wartime food production.
In 1919, her painting Evening in the Harbor was accepted by Art Institute of Chicago for its annual exhibition; this became her first official recognition as an artist.
"[2] In 1927, her painting Tinker's Hollow won the Landscape Prize from the National Association of Women Painters and Sculptors.
[2] She was active in the Philadelphia community as well, serving as a division head of the Civic Club, an organization to improve the city's public schools and build political power for women.