During this time Farmer took up cooking, eventually developing a reputation for the quality of the meals her mother's boarding house served.

[4] However, the book was so popular in America, so thorough, and so comprehensive that cooks would refer to later editions simply as the Fannie Farmer Cookbook, and it is still available in print over 100 years later.

[3] She began by teaching gentlewomen and housewives the rudiments of plain and fancy cooking, but her interests eventually led her to develop a complete work of diet and nutrition for the ill, titled Food and Cookery for the Sick and Convalescent, which contained thirty pages on diabetes.

Farmer was invited to lecture at Harvard Medical School and began teaching convalescent diet and nutrition to doctors and nurses.

[3] Farmer died in 1915 at age 57 of complications due to a stroke,[2] and was interred in Mount Auburn Cemetery in Cambridge, Massachusetts.