Mary-Kate Olsen has been hospitalized with a kidney infection, her spokeswoman told People magazine.

The 21-year-old actress reportedly entered the emergency room of a New York hospital on Monday.

"Mary Kate got a kidney infection," her rep, Nicole Caruso, told People. "She's resting comfortably and will be released in the next day or so."

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After a hiatus from acting, Olsen — who rose to fame on TV's "Full House" in a shared role with twin sister Ashley — began portraying an alluring Christian girl on Showtime's "Weeds" in September.

She also returns to the big screen in "The Wackness," co-starring Ben Kingsley. The film is slated for release next year.