Mary-Kate Hospitalized

Mary Kate OlsenMary-Kate Olsen has been hospitalized with a kidney infection.

PEOPLE is reporting the 21-year-old pint-sized actress went to a New York ER and was admitted to a hospital on Monday. Her rep told the mag, "Mary Kate got a kidney infection. She's resting comfortably and will be released in the next day or so."

No word on what caused the infection.