Mayor Richard Daley's office announced early Monday that she had been readmitted to Northwestern Memorial Hospital after experience flu-like symptoms, including nausea and dehydration.
Maggie Daley had been released from the hospital on Friday after experiencing similar symptoms. Two days before, she left the hospital following a 10-day stay for surgery to replace a metal rod in her right leg, which was weakened by treatment for cancer.
A spokeswoman for the mayor, Jodi Kawada, issued a statement saying cancer is not the issue now and that Maggie Daley's condition remains stable. The statement says doctors decided to keep Daley at the hospital for observation.
Daley has been fighting metastatic breast cancer since 2002.