She is a member of the New York, the Texas, and the South Carolina historical societies, and of many other learned associations, and has written on historical subjects. She has been an officer of Sorosis and of the Daughters of the American Revolution, and a director of the Daughters of the Confederacy and of the Memorial Association of Charleston. During the West-Indian Exposition in Charleston (1901) she was a member of the women's executive committee and one of the editors of the "Interlude," the women's paper issued during the exposition. Among her writings are: "The City of a Prince"; "Texan Types and Contrasts"; "Land of the Tejas"; "Earliest Texas"; "Judy Robinson—Milliner"; and a number of poems, short stories, and magazine articles. Mrs. Harby was the successful competitor for the prize offered for a "Flag Song" for the state of Texas.