She was hired by a number of prominent women, and eventually worked for the family of William S. Cowles, the brother-in-law of Theodore Roosevelt.

[4] In 1898, she became a clerk in the office of the surgeon general of the United States, but she regularly took leave to continue as a social secretary for various women, including Ida Saxton McKinley, and the wife of U.S. senator Elihu Root.

[7] Edith soon began to rely on Hagner and authorized her to release photos of the first family in hopes of avoiding unauthorized press candids.

[9] During her time working in the federal government, Hagner's brother Randall owned a real estate venture that profited from her social contacts.

Upon their marriage in 1915, James persuaded Hagner to give up her work to become mistress of Overhills, a large estate and grounds located in Catonsville, Maryland.