Kelly Macdonald is a Scottish actress who stars as “Margaret Schroeder” alongside Steve Buscemi in HBO’s Boardwalk Empire. She is also known for roles of “Diane” in Trainspotting, “Carla Jean Moss” in No Country for Old Men, and “Evangeline” in Nanny McPhee. She starred in Gosford Park, The Girl in the Café, and played “Delia Smith” in the television miniseries State of Play. Macdonald recently starred as "Helena Ravenclaw" in Harry Potter and the Deathly Hollows: Part 2. She is married to Travis bassist and backing vocalist Dougie Payne.

More about the show at the official Boardwalk Empire site.