(CNN) -- Actress Skye McCole Bartusiak, who played Mel Gibson's youngest daughter in "The Patriot," died Saturday at her home in Houston, her mother said Sunday. She was 21. "We lost our girl," Helen McCole Bartusiak told CNN.

While investigators have not determined a cause of death, Bartusiak had been suffering from epileptic seizures in recent days, according to her mother. Bartusiak's most visible role was as the young daughter of Mel Gibson's Revolutionary War "Patriot" character in the 2000 movie. Her movie acting career began when she was just 6 in 1999 with a role in "The Cider House Rules."