At age six, Claire began dance classes. At age nine, she was studying acting at the Lee Strasberg Theatre Institute.

Claires' early film career began around age 11 when she played a molested child in a student film produced by director Milos Forman, Dreams of Love. That year Claire also found her start in television on a special appearance on Law and Order; in this episode, she portrays a teenager who murders her lover.

Later in 1992, Claire auditioned for My So-Called Life and opted do the pilot for this short-lived television series instead of accepting Steven Spielberg's offer for a small role in his Schindler's List. The introduction of this critically acclaimed teen drama series however, only captured a limited audience according to television ratings. ABC cancelled the series after only one season.

Winona Ryder helped Claire obtain the role of Beth March in the cinematic adaptation of Louisa May Alcott's novel Little Women.

Claire later appeared in How To Make an American Quilt (1995) with Winona, and Home for the Holidays (1995) directed by Jodie Foster. Claires' idol, Foster encouraged the budding, young actress to attend college. After deferring for one year, Claire will be matriculating to Yale University in autumn 1998.

Baz Luhrmann's modern cinematic adaptation of William Shakespeare's Romeo & Juliet had caught the eye of Claire.The part of Juliet would later afford her a MTV Best Actress award and a growing, loyal following.