Miss Rosco was the daughter of the actor James Rosco and his wife Ann Barbara. For her stage début, she attempted the role of Zara in The Mourning Bride at Drury Lane Theatre on 9 February 1757, the prompter Cross recorded in his diary that she was “Indiff.” On 29 November 1758 at the New Assembly Room in Princess Street, Bristol, a benefit concert was held for her, when she sang for the first time in public.
During the 1759-60 season at the Crow Street playhouse, Dublin she sang Lucy in The Beggar’s Opera, and performed in the comedy of Love makes a man with Miss Osborne, both actresses were received with moderate applause.
Miss Rosco ‘had many claims on the public. Her figure and features, tho’ full, and rather masculine, were well adapted to the stage she had spirit, and possessed pleasing musical powers. Her forte lay principally in lively comedy, and singing characters, such as Lucy in the Beggars Opera. She remained several years in this kingdom esteemed and respected; at length, being rather disgusted at the situation in which she was, she resolved to try another. Having received an excellent education, and being mistress of many elegant accomplishments, she quitted the stage, and returned to Bath, where she opened a boarding school for young ladies, which she conducted with the highest reputation and greatest success. She died in 1789.
‘Miss Osborne was of a respectable English family; the misfortunes and death of her father, obliged her mother to retire with this, her only daughter to Dublin, where she lived with prudence and oeconomy. If fame is to be credited, the same chance which gave the abilities of Mrs. Oldfield to the world, discovered those of Miss Osborne. A gentleman of much theatrical knowledge, by accident one day overheard her reading the play of Venice Preserved to her mother; struck with the propriety and elegance of her manner, he a few days, after mentioned this circumstance to Mr. Barry, who was his particular friend, in so warm a manner, that Mr. Barry, in consequence of his request, visited the young lady, and from a few specimens which he prevailed on her timidity to give, found his friend had not exaggerated in his report of her abilities. The conclusion was, after some intreaty he prevailed on the mother to consent to Miss Osborne’s going on the stage, where she remained many years, and though her talents were not of the first rate, yet she sustained many second parts in tragedy and comedy with reputation, whilst her character in private rendered her an ornament to her profession. In process of time we shall find this young lady married to Mr. W. Barry, treasurer’.
An historical view of the Irish stage: from the earliest period down to the close of the season 1788. Interspersed with theatrical anecdotes, … In two volumes. … By Robert Hitchcock, d. 1809. Vol. II