Actress, noted for her roles as the tragic heroine. Born Margaret Somerville in Lanark, she was the eldest daughter of John Somerville, who later moved to London and established himself as a biscuit-maker. Her acting ability was noted at an early age and, encouraged by Lord Byron, she first appeared on stage as Imogine in Maturin's tragedy Bertram in 1816. She created the character Bianca in the first performance of the play Fazio by Henry Hart Milman. She also was notable as Lady Macbeth in the play by Shakespeare, Cornelia in Sheridan Knowles Caius Gracchus, Emma in William Tell, also by Knowles, and as Queen Elizabeth in the stage adaptation of Sir Walter Scott's Kenilworth.
Her portrait by Thomas Charles Wageman (playing Alicia in Nicholas Rowe's The Tragedy of Jane Shore) is in the Royal Collections and another portrait by Wageman where Bunn plays Hermione in Shakespeare's The Winter's Tale is held by the National Portrait Gallery.