She was nominated again for a Young Artist Award for her performance.Stewart's first starring role was at age 14 in the children's action-comedy Catch That Kid (2004), opposite Max Thieriot and Corbin Bleu.That same year, Stewart had a small role in the Sean Penn-directed adaptation Into the Wild.For her portrayal of Tracy – a teenage singer who has a crush on young adventurer Christopher Mc Candless (played by Emile Hirsch) – Stewart received mixed reviews.In 2015, she received critical acclaim for her role opposite Juliette Binoche in Clouds of Sils Maria, for which she won a multitude of accolades, including the César Award for Best Supporting Actress, making her the first American actress to win a César Award.
She recalled, "I never wanted to be the center of attention — I wasn't that 'I want to be famous, I want to be an actor' kid.
That year Stewart also played the role of Lila in the thriller, Undertow (2004).
Stewart starred in the Lifetime/Showtime television film Speak (2004), based on the novel by the same name by Laurie Halse Anderson.
Born in Los Angeles to parents working in show business, Stewart began her acting career in 1999 with uncredited roles and a minor character appearance in several films.
She gained notice in 2002 for playing Jodie Foster's daughter in the thriller Panic Room, which garnered her a Young Artist Award nomination for Best Leading Actress in a Feature Film.