Claire Clairmont
Clara Mary Jane Clairmont , or Claire Clairmont as she was commonly known, was the stepsister of writer Mary Shelley and the mother of Lord Byrons daughter Allegra.
She was born in 1798 in Brislington, near Bristol, the second child and only daughter of Mary Jane Vial Clairmont. Throughout her childhood, she was known as Jane. In 2010 the identity of her father was discovered as John Lethbridge of Sandhill Park, near Taunton in Somerset. Her mother had identified him as a Charles Clairmont, adopting the name Clairmont for herself and her children, to disguise their illegitimacy. It appears that the father of her first child, Charles, was Charles Abram Marc Gaulis, a merchant and member of a prominent Swiss family, whom she met in Cadiz.
Source: Wikipedia