Allyson and Avery Clark, 8-month-old formerly conjoined twins, slept in separate cribs across the room from each other at home Friday night.

Just three days after separation surgery, they left Primary Children's Medical Center late Friday afternoon.

The girls, daughters of Kerry and Anna Clark, who live at Hill Air Force Base, were joined at the lower back, their spinal cords looping down to meet in a U shape. Doctors separated them Tuesday in a surgery that took close to seven hours, about half of it spent prepping and arranging them.

It's different, but "great," the Clarks agreed, although Anna said she was slightly flustered the first time the twins fussed, since she's not used to having to choose which one to go to first.

She said she thinks the girls know something has changed, but they're pretty much unfazed, even when faced with a dozen TV and newspaper cameras. Allyson is the more vocal of the two, while Avery's "still hanging back, curious." Avery seems to miss having her sister right next to her more than Allyson does.

They still interact with each other. They've always poked each other and held hands and sometimes tugged on the other's ears. Now they're watching each other a lot more — when they're not playing with their "little mom," sister Rylee, 6, who saw them for the first time since the operation Friday morning.

Among the biggest differences is how easy it is to hold them, said Kerry Clark. "You can flip them around to look at you," he said as he cuddled Avery, who weighs 17 pounds. Allyson weighs 15. But combined, they had grown too big even for the "hippo" car safety seat the family had been using, originally designed for children with hip conditions that forced them to wear casts. There was no good high chair option, either. Minutes after Tuesday's surgery, the girls' dad was talking about how nice it was to have two of everything, all readily available from a store.

Scarring should be minimal, said Dr. Faizi Siddiqi, the reconstructive and plastic surgeon who inserted tissue expanders several weeks before separation so they'd have enough skin to cover their wounds and who later closed those wounds at the end of the surgery. They had plenty of skin, so there's no tension and that will help reduce scarring.

No one's sure if there will be complications down the road. Dr. John Kestle, the neurosurgeon who led the team, said they may have some bladder or bowel problems because the spinal cords were separated near where the nerves for those functions are located. Or they may not. At this point the infants are soaking their diapers just fine and it will take time and tests to see if they're emptying their bladders completely or partially.