Between the Bourne films, she appeared in Mona Lisa Smile (2003) as Joan, a student at Wellesley College in 1953, whose art professor (Julia Roberts) encourages her to pursue a career in law rather than become a wife and mother.
Imellem Bourne-filmene, optræder Stiles i Mona Lisa Smile fra 2003 som Joan, en studerende på Wellesley College i 1953, hvis kunstlærer (Julia Roberts) opmuntrer hende til at gå efter en karriere inden for jura i stedet for at blive kone og mor.