"We have more than one ethicist who thinks these girls don't need to be separated," Meyers said. "Mom and Dad have had a chance to hear all of that and talk to people on both sides."

Before making their decision earlier this year, the Herrins had Kendra and Maliyah talk with a psychologist. The couple concluded that while the girls expressed some fear about the surgery, separate "was how they saw themselves when they were older," Jake Herrin said.

The twins are outgoing and greet a visitor with a cascade of curious questions - "What's your name?" "Do you like Barbie?" "Do you like my hair?"

To prepare them for surgery, doctors inserted 17 expanding balloons into the twins' torsos in June. Filled with saline solution, the balloons stretch the skin and muscles, giving doctors more tissue to work with during plastic surgery after the separation. Each week more saline has been added to the balloons.

The process has been more painful than expected and the skin over a least one expander has been slow to heal, delaying surgery by a week. To reduce the pressure on their tender skin, the girls sleep on a 3,000-pound oval hospital bed that is filled with sand.

To help them understand what is about to happen to them, Kendra and Maliyah have been given a set of conjoined stuffed dolls to play with. Like the girls, the dolls get Band-Aids and shots. On July 20, Kendra performed separation surgery on the dolls, as Maliyah looked on.

"They gave the babies medicine and said that they were so brave," Erin Herrin wrote in a posting on the North Salt Lake family's Web site. "It is incredible to us how much they really do understand."