SLC’s youngest daughter was named after his mother, Jane Lampton Clemens, but was always called Jean. Like her sisters, Jean was educated largely at home. In 1896, however, she was attending school in Elmira, New York, when she suffered a severe epileptic seizure. Sedatives were prescribed, and for the next several years her anxious parents tried to forestall the progress of her illness, even spending the summer of 1899 in Sweden so that Jean could be treated by the well-known osteopath Jonas Kellgren. Her condition, which worsened after her mother’s death in 1904, and the household’s frequent relocations, gave Jean little chance to develop an independent existence. During this period she taught herself to type so that she could help her father by transcribing his manuscripts. She also loved riding and other outdoor activities, and espoused animal and human rights causes. In October 1906 Jean was sent to a sanatorium in Katonah, New York, remaining in “exile” until April 1909, when she rejoined her father at Stormfield. Over the next months she enjoyed a close, happy relationship with him and took over Isabel Lyon’s duties as secretary. Jean died at Stormfield on 24 December 1909, apparently of a heart attack suffered during a seizure.