The cause of death was not immediately known, according to Variety, but she reportedly died in her sleep Saturday while at her Texas home.
A family spokesperson described her as "a brave and caring young woman" who is "deeply missed by her family and friends," reports Deadline.
As a child star, the Texas native also appeared in The Cider House Rules (1999), Don't Say a Word (2001) and Boogeyman (2005). According to her IMDB page, she most recently starred in a short 7-minute comedy called Frame of Reference (2013).
Bartusiak also made her way to the small screen on shows such as 24, Lost, CSI: Crime Scene Investigation and House M.D.