Lilly Moscovitz is a character featured in the movie, The Princess Diaries. She is portrayed by Heather Matarazzo. She is Michael Moscovitz's younger sister and Mia Thermopolis's best friend. She shows a strong sense of resolve when it comes to a subject she loves. Lilly and Mia grow apart after Mia dumps Michael, later  Lilly confesses that she was upset with Mia because she believed she had taken J.P. from her. She speaks clearly and loudly, and Mia doesn't always grasp her large vocabulary. Since kindergarten, she and Mia have been great friends, and Mia considers her to be one of her heroes.