Once-Conjoined NY Twins Make Debut at Pa. More than nine months after they were born joined at the lower chest and abdomen, twin girls made their public debut Thursday at the hospital where they were separated. Allison June and Amelia Lee Tucker, clad in animal-striped shirts and flowered headbands, were introduced during a news conference at Children's Hospital of Philadelphia. Both girls still have nasal tubes but appeared rosy-cheeked and alert as they were held by their parents, Shellie and Greg Tucker, of Adams, N.Y., about 300 miles north of Philadelphia near Lake Ontario. Allison, described by doctors and her parents as the smaller but feistier twin, was discharged from the hospital Monday. Her sister Amelia, who's larger and more reserved, needs a little more recovery time and will remain in the hospital into the new year. "We totally expect them to have full, independent lives," said pediatric surgeon Dr. Holly Hedrick, who led a 40-person medical team in the complex seven-hour operation on Nov. 7. Shellie and Greg Tucker, parents of Allison, left and Amelia, present their nine-month-old girls who were formerly conjoined twins at Children's Hospital of Philadelphia (CHOP) Thursday, Dec. 20, 2012, in Philadelphia. Surgeons at CHOP separated the Tucker girls during a seven-hour operation in November. The infants from Adams, N.Y., had been joined at the lower chest and abdomen. They shared their chest wall, diaphragm, pericardium and liver. (AP Photo/Matt Rourke) Close The twins shared a chest wall, diaphragm, liver and pericardium, the membrane around the heart. Shellie Tucker was about 20 weeks into her pregnancy when she learned she was carrying conjoined twins. Prenatal screening tests at Children's Hospital, including ultrasound imaging and MRI, determined that they would be good candidates for separation. Planning for the separation surgery began months before the twins were delivered by cesarean section on March 1. Shortly after they were born, plastic surgeons inserted expanders under the girls' skin to increase the skin surface available to cover exposed organs after their separation. Shellie Tucker described the past year as a "roller coaster ride" but said she was relieved now that her daughters are doing so well. "The burden is completely gone, and I am very, very happy," she said. The surgery was the 21st successful separation of conjoined twins performed at the hospital. The first was in 1957. According to statistics provided by the hospital, conjoined twins occur once in every 50,000 to 60,000 births and about 70 percent are female. Most conjoined twins are stillborn. Children's Hospital of Philadelphia: http://www.chop.edu