Emma, In London and Paris, Doing Shakespeare

In the Autobiography, EHB has this to say about her move to the United States in 1855:

The last night of the English Wallack Company's performances (in Paris) had arrived; on that occasion I played in a little character piece of my own writing, and at its close, our most intimate friend in Paris, being, as was his custom, behind the scenes, introduced me to a gentleman whom I found talking with this friend and my mother, and endeavouring to convince her that the best and most attractive spot on earth for the display of my peculiar talents, etc., etc., was the B— Theatre, of New York, of which he himself was the manager. He had watched me playing various parts many nights, he alleged, and had determined to engage me, and go to New York I must, and that immediately.

Compare that, with this, from The Principal Dramatic Works of Thomas William Robertson (1889):

Coming to the year 1855, [Robertson] was engaged by his father and J. W. Wallack, then partners in the management of the Marylebone Theatre, for juvenile lead...Robertson, together with the entire company, accepted an offer to go to Paris for the purposes of producing Macbeth at the Theatre des Italiens....The whole affair was a terrible failure and did not last three weeks, the company receiving but one week's salary." (pp. xxx-xxxi)

Other summaries of this company's Macbeth are even more harsh, and suggest plainly that the cast was effectively stranded in Paris.

For example, Maynard Savin's Thomas William Robertson: His Plays and Stagecraft (1950) includes this description

Robertson's first substantial acting engagement since he had struck out on his own in London was ironically due to family connections. William Robertson and J. W. Wallack in 1855 were managing the Marylebone Theatre. Robertson's brother
Craven and his sister Madge were playing juveniles. Tom rejoined the family. They played a season. Then, whether it was because the touring instinct was overpowering or the Marylebone vein had been exhausted, the Robertsons were off on another fantastic gamble a visit to Paris to produce Macbeth at the Theatre des Italiens. The company was impressive, including the Wallacks, the William Robertsons, Mrs. Arthur Stirling, and George Honey, but the name of the angel was prophetic: Monsieur Ruin de Fee. The foreign tour lasted less than three weeks; the company received one week's salary, and the actors straggled back to London as best they could.

Though the details differ (the theatre names, for example), this does tend to confirm EHB's story about this particular period of her life. She speaks, earlier in the biography, of going to Paris with a company to do Shakespeare, and she mentions a G.H., whom she knew and who effectively recruited her into the company. That would be either George Honey, or George Bennett Hoskins (or Bennett-Hoskins), who are noted as among the company in The Principal Dramatic Works..., and, as Bennett Hoskins was from the Sadler's Wells company, where "Miss Emma Harding" had done Macbeth and Othello in 1844 , I'm inclined to bet on Bennett Hoskins as the G.H. of the Autobiography, although "Miss Emma Harding" did perform with George Honey at the Adelphi in August of 1853 in (kid you not) What, No Cab?.

Increasingly difficult not to draw the equation "Miss Emma Harding" = "Emma Hardinge Britten"