Lizzie Olsen is this year's "It" Girl

Lizzie Olsen at Sundance Channel HQ.

A week ago, Elizabeth “Lizzie” Olsen was just another 21-year-old senior at NYU who happened to have two very famous half-sisters: the TV-movie-fashion-and-overall-marketing phenomenon known as Mary Kate and Ashley.

This week, thanks to the Sundance Film Festival, where she’s starring in two much-buzzed about films (MARTHA MARCY MAY MARLENE and SILENT HOUSE) the “third” Olsen has been a hot topic on Twitter; has been unilaterally declared the festival’s “It” girl (a prestigious, not to mention very hip, crown worn previously by Zooey Deschanel, Carey Mulligan, and Parker Posey); and has just landed a role in a big, Hollywood movie—RED LIGHTS, a psychological thriller directed by Rodrigo Cores (BURIED), and starring Robert DeNiro and Sigourney Weaver.

But if Lizzie—who looks uncannily like her sisters, even though she’s not 100 percent blood-related—is poised to overtake their fame, she’s doing it in her own distinct, and very stripped-down. No drapy, hobo-style skirts, and layers of necklaces, for this girl. At the MARTHA premiere, Miss Olsen—who is the namesake of Mary-Kate and Ashley’s more youthful line, Elizabeth & James—was dressed sensibly in a green cardigan, skinny black jeans, and trim overcoat–more like she was heading off to an Ivy League seminar than a hipster film screening. (In contrast, Deschanel showed up to the premiere of MY IDIOT BROTHER, in keeping with the quirky, anything-goes ethos of Sundance, decked out in a purple satin dress, black tights, and clunky, pink heels.) Not that Lizzie doesn’t rock her own version of the Olsen’s, indie-chic style. On Friday, she showed up for an interview with the Sundance Channel, wearing black leather pants, a great T-shirt, and flat-heeled boots. Her fingernails were painted lavender.

Lizzie’s presentation is also more straight-up, less coy, than her sisters’. When talking to the hordes of reporters who have been hounding her over the past few days, she exudes a sunny, unapologetic, confidence. There is no sign of the meek-mouse cutesiness that became Mary Kate and Ashley’s trademark back in the early 2000’s, when they were traipsing around New York City, having dalliances with Greek shipping heirs and dodging the paparazzi by ducking into corner stores. Nor is there—yet, anyway—any sign of some the Olsen’s unstable behavior (rehab, anorexia, etc.)

The It Girl, it seems, is also the Good Girl.

For more of Nicole’s dispatches at the Sundance Film Festival see her blog on The Daily Beast.