She was the daughter of minor actress, Mrs Bellamy, (née Seal) and James O'Hara, 2nd Baron Tyrawley, who paid for her education.

When she died, she had little money to her name and was living under the rules of the King's bench prison in her final residence in Eliot's Row, St George's Fields.

[7] Bellamy had a successful career that although began by luck, was subsequently built on talent, hard work and determination.

Impressed, he engaged her as a performer and she made her professional debut on 22 November 1744, aged thirteen playing Monimia in The Orphan.

Prior to her professional debut, she had already performed in Covent Garden in one of her very first roles, a non-speaking part as the servant to Colombine in the Harlequin Barber in 1741.

Whilst she was there she found patronage with a Mrs Butler who helped her to unseat Fanny Furnival from the role of Constance in King John.

In Covent Garden it was David Garrick and Bellamy while Drury Lane had Spranger Barry and Susannah Cibber playing the title roles.

Bellamy, unhappy with this decision, decided to take matters into her own hands and created and distributed hand-out sheets to the audience, stating that the role had been taken from her the night before.