UPDATE 2/28: Sean Lennon revealed his mother has been released from the hospital:

ORIGINAL STORY: Yoko Ono was hospitalized for flu-like symptoms last night (Feb. 26).

The FDNY told CBS New York Ono was found unconscious in her New York City apartment and rushed to a nearby hospital. Original reports indicated she suffered a stroke, but a representative for the 83-year-old artist told the Associated Press Ono was admitted to New York’s Mount Sinai Roosevelt Hospital for flu-like symptoms on the advice of her doctor and she is expected to make a full recovery. She could be dischraged as soon as today.

In a tweet, Ono’s son, Sean Lennon, wrote his mother was dehydrated and tired but fine:

Ono released Yes, I’m a Witch Too, the second installment in her covers and remixes series, last week. It compiled tracks from Death Cab for Cutie, Peter, Bjork and John, Sparks, Portugal. The Man, Tune-Yards and more. The first edition, Yes, I’m a Witch, arrived in 2007 with contributions from Cat Power and the Flaming Lips.