Barbara Bush Hospitalized in Houston

Updated at 12:33 a.m. ET

Former first lady Barbara Bush was admitted to a Houston hospital Saturday morning to undergo medical tests and is expected to be released within the next few days.

Jean Becker, chief of staff for former President George H.W. Bush, told CBS News that doctors don't expect the 84-year-old former first lady to be in the hospital for more than a day or two. Bush was in good spirits, Becker said.

Bush is undergoing routine tests based on her doctor's suggestion, Becker told CBS Radio News.

Bush actually went to The Methodist Hospital in Houston on Friday after reading to two classes at Barbara Bush Elementary, but she returned Saturday morning to be admitted, Becker told CBS News. Mr. Bush drove his wife to the hospital, Becker said. Becker didn't expect Bush's condition would be updated until the tests are done.

CBS News affiliate station KHOU-TV in Houston reports that the former first lady hasn't been feeling well for a couple of weeks.

A Bush family member offered a more candid assessment of the family matriarch's condition.

"She's fine," Neil Bush told CBS Radio News. "There's nothing to freak out about."

This is the third time the former first lady has been admitted to the hospital in the past two years. Her aortic valve was replaced just over a year ago. She underwent surgery for a perforated ulcer in November 2008.

Fox News first reported about Barbara Bush's hospitalization Saturday night.

"Mrs. Bush is in for routine tests as she hasn't been feeling at the top of her game," Bush spokesman Jim Appleby told Fox News. "We anticipate her release soon."