SANTA MONICA, Calif. - Nancy Reagan has been undergoing more tests at a California hospital today.

The former first lady was hospitalized at St. John's Health Center, Sunday, after falling in her home in Bel-Air, but is doing well, her spokeswoman Joanne Drake said.

She spent the night there as a precaution. Doctors there determined yesterday that she did not break a hip. But it's not clear just when she'll be released from the hospital.

Drake said Reagan, 86, was "doing fine" and is in "good spirits."

"She's joking and visiting in her room," she said.

Nancy Reagan's last major public appearance was in January, at the Republican presidential debate at her late husband's library.

At St. John's, she stayed the night in the same room where former President Ronald Reagan stayed after he broke his hip at home in 2001. He died June 5, 2004, after a 10-year battle with Alzheimer's disease. The two were married for 52 years.

Source: The Associated Press