Jade and Erin Buckles, the 4-month-old conjoined twins who were surgically separated Saturday at Children's Hospital, are recovering without complications.

Erin was removed from a mechanical ventilator yesterday and is breathing on her own, said John T. Berger, a physician in the pediatric intensive care unit, where both babies are being treated. Jade probably won't come off her ventilator for a day or two.

"They're both doing better than hoped for," Berger said. "They're just a delight. Erin is the big star of the day."

The babies have had no bleeding episodes and show no evidence of infection -- two of the big risks after major surgery. The function of their hearts is normal, and neither is on any heart-stimulating drugs, he said.

Erin was fully conscious and "looking around" after her breathing tube was removed in mid-morning, Berger said. Jade is heavily sedated and will remain so until her tube is removed. About 10 people a shift are involved in their care, although most are not attending them exclusively.

The sisters, born Feb. 26 at the National Naval Medical Center in Bethesda, were attached from mid-chest to mid-abdomen. Their livers were fused, and their hearts occupied a common protective sac, or pericardium. During the operation, the surgeons also discovered a small bridge of tissue connecting their hearts and causing them to beat in unison.

The twins were separated in a six-hour operation performed by a team of two dozen physicians, nurses and technicians. Although the girls' own skin was used to cover the large openings on the fronts of their bodies, some of the layers beneath the skin were closed using synthetic materials.

Erin's heart partially protruded from her chest into her sister's when they were connected. The surgeons redirected the tip of her heart slightly when they built a new pericardium using the native tissue supplemented by Gore-Tex fabric.

Both girls were started on intravenous nutrition Tuesday. Berger said the medical team hoped to start giving Jade a small amount of liquid feedings late yesterday through a tube running from her nose into her stomach. Adequate nutrition is essential for wound healing, with oral feedings preferable to intravenous ones.

Both girls are also temporarily on antibiotics to help prevent infection.

The twins are the daughters of Melissa and Kevin Buckles of Woodbridge. Their mother is a high school teacher, their father a Marine gunnery sergeant stationed in Washington.

Children's Hospital officials believe the cost of the surgery and post-operative care will be at least $750,000, and possibly as much as $1.5 million.

Grandmother Jean Buckles was overcome as family members visited twins Jade and Erin on Sunday for the first time since they were separated. In back are father Kevin Buckles, his sister, Connie, and the babies' mother, Melissa.