Claire Clairmont

 was a stepsister of Mary Shelley. She had an affair with Percy Shelley, her stepsister's beloved, but was in love with Lord Byron and was carrying his child in June 1816. (AUDIO: Mary's Story; TV: The Haunting of Villa Diodati)

She saw the Eighth Doctor's "death" and "resurrection" at the Villa Diodati. (AUDIO: Mary's Story)