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.
"Absolutely relieved," said Shellie Tucker. "It was overwhelming. It was emotional. It was such a relief to have it over with."
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.
Dr. Holly Hedrick led a team of 40 doctors, nurses and staff during the 7 hour separation surgery. She says seeing one become two was amazing.
"It is an overwhelmingly dramatic moment when the tables spread and the babies go their separate ways," said Dr. Hedrick.
"From the ultrasound starting off back in November to now, two separate healthy babies, I don't think that I could really ask for much more," said Greg Tucker.
The family, including big brother Owen, were hoping to have both twins home for Christmas.
"It's still a success," said Shellie. "We kept saying if we weren't going to have them home by Christmas, we wanted to know at least that they are both doing well, and that we will be going home soon. And know that is a miracle."
"We totally expect them to have full, independent lives," Dr. Hedrick 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.