Michelle Williams Channels Marilyn Monroe in New Film

Michelle Williams eschewed the chair and sat on the floor of the private dining lounge at the Beverly Hills Hotel, sipping a cup of tea.

Much more comfortable, she said, crossing her legs and unwrapping a granola bar.

The night before, Williams, 31, had flown into Los Angeles for 48 hours from shooting Oz: The Great and Powerful playing Glinda the good witch.

At that moment, however, Williams was out of that head space and focusing on another enchanting woman who weaved her magic on American cinema: Marilyn Monroe.

Williams stars as the iconic starlet in the indie film My Week with Marilyn, based on Colin Clark's book of the same name and opening in U.S. theaters on November 23.

It chronicles the author's experience of spending a week with Monroe in 1956 while she was in England shooting the romantic comedy The Prince and the Showgirl opposite Sir Laurence Olivier.

This isn't the Marilyn Monroe story, so the movie is not a tragedy, Williams said. It's a movie that Marilyn Monroe happens to be a character in.

It's also the type of movie that may resonate with Oscar voters. Williams has been Oscar-nominated twice, as best supporting actress for Brokeback Mountain and best actress for 2010 drama Blue Valentine.

Now, as she embodies one of Hollywood's own, Williams may find herself on a winning streak. Between 2000 and 2010, seven of the best actress Oscar wins were for roles depicting real people including Sandra Bullock (The Blind Side), Marion Cotillard (La Vie en Rose) and Helen Mirren (The Queen).

Williams laughed off the thought.

I try not to live in the future because it's crazy! she said with a blush. I'm just relieved that I paid a proper homage, because I didn't want to let her down.

She was referring to Monroe and the research and physical transformation it took to embody the legendary actress.

I watched every movie countless times, Williams explained. The Internet became a great research tool. There were a few fronts that were up and running simultaneously -- the physical, the facade, and her essence.

MOVING LIKE MONROE

One of those was the way Monroe moved. Williams described it as a series of continuous poses, completely fluid, but at any point if you stopped, you could take a picture and it would be a perfectly set up pose.

Gesturing with her hands, she continued: It looked like she loved her body, loved touching her body, loved referencing it, loved being able to guide people's attention to where she wanted them to look.

Though in person the waif-like Williams bears little physical resemblance to Monroe, in the film, she is as voluptuous as Monroe.

Were those her real hips? Or padding? Can she talk about which body parts were hers and which weren't?

Apparently not, she demurred. Apparently my director had some other ideas about it.

I was definitely heavier than I am now, but I really don't know how much, she added. But there are ways that she and I will never meet physically. For certain things, no matter what I do, I won't be able to achieve that sameness...I was never going to get a body like hers!

What Williams does have is a singing voice and coordinated feet. The actress does all the singing and dancing in the film, despite her only previous such experience being as a child doing children's theater.

Who knew I would actually sing and dance in the movie? I had a blast! said Williams.

Despite the fun, Williams was keenly aware of Monroe's tragic side -- the pills, the alcohol, the marriages and her co-dependency on other people.

Something about her said, 'Love me, protect me,' and a lot of people took that on and felt a kind of devotion to her, mused Williams.

Many people felt a similar protectiveness toward Williams when in 2008, her former boyfriend and Brokeback Mountain co-star Heath Ledger died of an accidental drug overdose, making the actress a single mother to their child, Matilda, who is now 6 years-old.

Though Williams declined to drudge up that past, she did say that unlike Marilyn, I'm not in as needy of a place, although I think I was when I played the (Marilyn) role. I found myself becoming far more dependent and clingy in a way that I had never done before.

Luckily, I have a stabilizing force, which is my daughter, she continued. I often think, if Marilyn had a kid, she would have pulled through, I really do.