<P> In 1998, Davidtz played a theologian helping Denzel Washington crack a supernatural wave of crimes in the mystery drama Fallen and a femme fatale linked to Kenneth Branagh in Robert Altman's take on a previously unused John Grisham manuscript, The Gingerbread Man . The following year, Davidtz portrayed a 19th - century woman of the world in Patricia Rozema's reworking of the Jane Austen comedy Mansfield Park and played a dual role opposite Robin Williams in the futuristic fable Bicentennial Man . </P> <P> A supporting role in the film adaptation of Bridget Jones' Diary (2001) saw Davidtz play Natasha, a colleague and one of the love interests of Mark Darcy (Colin Firth). That year, she began her run on the CBS drama, Citizen Baines, playing the daughter of a defeated United States Senate incumbent (James Cromwell) who is herself leaning towards a career in politics . Other roles included horror thrillers like 2001's Thir13en Ghosts . In 2002, she appeared in the Michael Hoffman drama, The Emperor's Club, which co-starred Kevin Kline and Emile Hirsch . </P> <P> In Junebug (2005), Davidtz played an outsider art dealer from Chicago brought to North Carolina by her husband (Alessandro Nivola) to meet his family for the first time . Davidtz has also guest - starred on the hit ABC drama series Grey's Anatomy as Dr. Derek Shepherd's sister Nancy in the Season 3 episode "Let the Angels Commit". In 2008, she had a regular role on HBO's In Treatment as Amy, part of a fractious couple alongside Josh Charles's Jake . </P> <P> She portrayed the unfaithful and unfortunate wife of Anthony Hopkins's character in the 2007 drama Fracture . </P>

Who plays derek's sister nancy on grey's anatomy