Jane Lampton "Jean" Clemens (July 26, 1880 – December 24, 1909) was the youngest of the three daughters of Samuel Langhorne Clemens, better known by his pen name Mark Twain, and his wife Olivia Langdon Clemens. On Christmas Eve 1909, Clemens drowned in a bathtub at her father's home following a heart attack thought to be related to her epilepsy.