But it's Mulligan who is wooing the critics with her first lead role in a movie.
Even though she remains cool about it, Mulligan's turn in the coming-of-age movie "An Education," which opens in the United States on Friday, has set Oscar watchers buzzing and led one U.S. movie critic to compare her to screen icon Audrey Hepburn.
Critics are impressed with how Mulligan, 24, played a 16 year-old in a romance with a grown man, but the actress said she cannot pinpoint what they see in her performance.
"The first time I watched it I was really upset, because I thought it was really boring," Mulligan told Reuters.
"If you watch your own face for that amount of time, there's nothing particularly interesting to you about your own face," she said.
As for those who say Mulligan could be nominated for a best actress Oscar for "An Education," the daughter of hotel industry workers said the buzz is bewildering.
"It's sort of a bizarre thing to think about," she said. "Obviously, it's really flattering."
In "An Education," Mulligan plays London schoolgirl Jenny, who forgets her dreams of attending Oxford University when she meets a daring man twice her age named David (Peter Sarsgaard) and falls for him during trips to Paris and the orchestra.
Set in the early 1960s, the movie from BBC Films explores Jenny's "education" in love and deception, as David charms her parents into acquiescing to the romance, before revealing himself to be something more than he admits to.
"An Education" opens in limited release in New York and Los Angeles on Friday before expanding to other cities. It debuts in England on October 30.
In Entertainment Weekly magazine's Oscar Watch blog, writer Dave Karger said, "She's going to charm the pants off the Academy (behind the Oscars) and should have no problem scoring a best actress nomination."
Influential Chicago Sun-Times movie critic Roger Ebert, writing of Oscar prospects, said; "Who looks like a sure thing for nomination? Carey Mulligan from 'An Education,' I'd say. The scenes in Paris will remind you of Audrey Hepburn."
The annual awards season gets underway toward the end of the year with the Academy of Motion Picture Arts and Sciences being the last to announce its nominees in February 2010.
Mulligan said the reaction to her performance is especially surprising because "An Education" is her first lead role, and when it premiered in January at the Sundance Film Festival, the team behind the movie was not sure it would get picked up for wider distribution.
Mulligan had supporting roles in the 2005 film "Pride & Prejudice," based on the Jane Austen novel, and the 2005 BBC television adaptation of Charles Dickens' "Bleak House"
Her brother went to Oxford University, and with a grandmother who suffers from Alzheimer's disease, Mulligan said she might one day study psychology and mental illness.
But for now, she said acting gives her "an education."
"You're thrown into a world where you meet people who aren't your age," she said. "Maybe you grow up a bit faster."
(Editing by Jill Serjeant)
COPYRIGHT: (c) Reuters 2009. All rights reserved. Republication or redistribution of Reuters content, including by caching, framing or similar means, is expressly prohibited without the prior written consent of Reuters. Reuters and the Reuters sphere logo are registered trademarks and trademarks of the Reuters group of companies around the world.