12/20/2010 01:35 pm ET Updated May 25, 2011

Conan O'Brien's Sister, Kate O'Brien, Makes Cameo In 'The Fighter' (PHOTO)

Tall, red headed, from Massachusetts and working in show biz... Anyone come to mind?

If you're thinking Conan O'Brien, you're half right -- it's his sister, Kate. The Boston native plays a quick cameo in 'The Fighter,' a film about an Irish Catholic family from Lowell, Massachusetts.

Kate plays Mickey (Mark Wahlberg) and Dicky (Christian Bale's) sister Phyllis Eklund, and says the role was a natural one for her (she's on the far right in the photo below).

"I work at a school and someone said, 'They're casting ['The Fighter'], you should go down, you look Irish Catholic,' " Kate O'Brien told PEOPLE Magazine. "I'm one of six, so it wasn't that hard for me to look like I might have more siblings [in the movie]."