Elizabeth Olsen on Her Siblings' Style, New Film 'Liberal Arts'

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"I steal a lot of their clothes. It's awesome. Ones that fit," says the "Liberal Arts" ingenue.

As the younger sibling of Mary-Kate and Ashley, Elizabeth Olsen has ventured into territory that might cause even the most jaded fashionista to faint upon sight: the tiny twin moguls' closets, no doubt stocked with designer labels and one-of-a-kind vintage.

"I steal a lot of their clothes. It's awesome. Ones that fit. They're very little," the 23-year-old actress and It Girl told THR on Monday at the New York premiere of her latest film, Liberal Arts.

Olsen's cool-girl, casually glamorous style often mimics that of her sisters. But she confessed, "I'm not as clever as they are. I just kind of steal things from what they already do."

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With New York Fashion Week in full swing, the former Full House stars-turned-fashion darlings presented the latest looks from The Row, their upscale label, earlier Monday at the posh Carlyle Hotel near Central Park.

"I've never been to a classier event in my life! I loved every moment of it -- at the Carlyle (with) the tea and the pastries, and the clothes were insanely gorgeous," said Olsen, looking ladylike in a sand-colored party dress with a full skirt. "It was ridiculous. Mary-Kate was, like, on my lap and we were watching it and it was really beautiful."

Olsen, meanwhile, is fast becoming as famous as her siblings. Her breakout role as a cult escapee in 2011's Martha Marcy May Marlene won wide acclaim, leading to parts in the upcoming films Very Good Girls (opposite Dakota Fanning) and Spike Lee's Oldboy remake.

(The latter movie begins production next month, and Olsen teased: "It's gonna please fans and people who've never heard of it." As for Lee, "I find him to be the most kind, generous, funny person. I love being around him.")

In Liberal Arts, which opens Friday, Olsen portrays Zibby, a 19-year-old Midwestern college student who falls for a 35-year-old admissions counselor (Josh Radnor) from New York when he comes to campus to visit a former professor (Richard Jenkins). Radnor, perhaps best known as Ted Mosby on CBS' How I Met Your Mother, also wrote and directed the film, and cast Olsen soon after the two convened for a 90-minute read-through of the script.

"I'm very happy and I feel fortunate to be able to have a choice of what I do next," she observed. "And I know it's not going to last forever so I'm just like holding on to it when it's happening now and for hopefully years to come. Good things never last forever though."

Twitter: @ErinLCarlson

Email: erin.carlson@thr.com