Barbara Bush remains hospitalized in Houston Former first lady Barbara Bush attends a White House ceremony to recognize the Points of Light volunteer program in Washington, DC, July 15, 2013. HOUSTON -- Former first lady Barbara Bush was "doing great and responding well" on Thursday while undergoing treatment at a Houston hospital for a respiratory-related issue, a family spokesman said. The wife of former President George H.W. Bush has been hospitalized since Monday at Methodist Hospital in Houston. There was no timetable for her release, but "we're hopeful that will take place sooner rather than later," family spokesman Jim McGrath said. McGrath told CBS News on Wednesday that it would not be "inaccurate" to characterize her condition as pneumonia. McGrath said physicians merely may be exercising extra caution by keeping her at the hospital. "She is 88," he said. She is a national treasure. She and her husband, the 41st president, live in Houston. They are the longest-married presidential first couple and will celebrate their 69th wedding anniversary on Jan. 6. The former first lady had a reputation for bluntness when her husband was president. Her son, George W. Bush, was the 43rd president. But health concerns had been more common of late with her 89-year-old husband, the nation's oldest living former president. George H.W. Bush was released in January 2013 after he spent nearly two months at Houston Methodist Hospital, being treated for a bronchitis-related cough and other health issues. The former first lady and her husband still make public appearances. Last week, they appeared at an event at the former president's office to honor a Houston businessman and philanthropist with a Points of Light Award, a volunteer service award started by Bush.