Emma's American stage début was as lead in a grand concert at the Jenny Lind Theatre, San Francisco, on 6 May 1852.
For much of 1852 The Waller Troupe, which included a young Edwin Booth, toured the northern Californian mining towns on horseback.
Returning to London, Mrs. Waller made her début at the Drury Lane on 15 September 1856, as Pauline in Bulwer-Lytton's The Lady of Lyons.
If his judgment is correct, she must have grown appreciably in physical and intellectual intensity, for she became one of the leading emotional actresses on the American stage.
She was described as "of stately presence, neither slender nor stout in person, and had an interesting and expressive face" (New York Dramatic Mirror, post, p. 17).
Her first appearance in New York was on 5 April 1858, as Marina to her husband's Ferdinand in a new version of John Webster's tragedy, The Duchess of Malfi.
She was also one of a number of actresses who seemed to take pleasure in impersonating male Shakespearean characters, among the most noteworthy of these being her interpretations of Hamlet and Iago.
Ill health finally compelled her to abandon all active professional work, and she lived in complete retirement at the home of her son in New York, where she died.