Mary-Kate Olsen To Guest Star On 'Samantha Who?'

LOS ANGELES, Calif. -- Mary-Kate Olsen will get back to her primetime roots with a guest star appearance on ABC's "Samantha Who?," Access Hollywood has learned.

The former "Full House" star was on set for a second day Tuesday, according to People.

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Mary-Kate will reportedly play a "self-destructive bad girl" in the comedy series, starring Christina Applegate. Despite her bad girl status in the episode, the actress was all business, according to "Samantha" Executive Producer Don Todd.

"She showed up alone, ready to work, is great on set and is serious about the job," Todd told People. "This is a girl who's been in front of the camera almost literally her entire life. She's smart, and she knows what she's doing."

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Mary-Kate fans who just can't wait until the fall TV season when "Samantha Who?" returns, can see the actress in "The Wackness" with Ben Kingsley in theaters July 3.