Jenna Bush, 19, one of President-elect George W. Bush’s twin daughters, is recovering this morning after undergoing an emergency appendectomy yesterday, having been rushed to a Texas hospital with complaints of abdominal pains. The younger Bush, a freshman at the University of Texas at Austin, was taken to St. David’s Hospital, near the Governor’s mansion, where she had been spending her Christmas with her twin sister Barbara (named for her grandmother), her parents and other family members. NBC News reported this morning that the patient is expected to be released today before joining her family on a Florida vacation tomorrow.