[2] She made her debut on the stage in Charleston, South Carolina under the patronage of actress Sarah H. Timm in 1842.

From 1845 until 1852, she was engaged at the Park Theatre in New York, where she had a successful career, performed with stars such as George Clifford Jordan, Annie Walters, Charlotte Saunders Cushman, Edward Loomis Davenport and William Pleater Davidge, and was called “one of the most beautiful women on the stage”.

Horn made her Montreal stage debut on July 14, 1852, playing Mrs. Ormsby Delmaine in The Serious Family.

In 1864, she settled permanently in Montréal, where she was one of the star actors of the Theatre Royal and a respected member of the fashionable society in Montreal.

She retired from both management and acting in 1880, but continued to be active in the theatrical life of the city.