Conjoined twins separated during a 26-hour surgery were breathing on their own, a milestone just days after the operation.

Kendra and Maliyah Herrin, 4, were removed from ventilators Saturday afternoon, said Primary Children's Medical Center spokeswoman Laura Winder, who called it "wonderful progress."

"It's a little sooner than perhaps we expected, but (doctors) said all along we would listen to how they were responding and follow their lead," she said.

Doctors also reported no evidence of post-surgery infections, Winder said.

The twins, who were born joined at the mid-torso, remain in critical but stable condition. They were separated during surgery that ended Tuesday.

Their father, Jake Herrin, said Maliyah's ventilator was removed about 10 minutes before Kendra's "but we'll call it a tie."

"They are doing great," he said on the family's Web site. "They have woken up but are still really drugged, so they really don't know what's going on."

On Friday, it seemed Kendra might be the first to come off the ventilator. But, as with each step in their recovery, when one twin shows improvement or change, the other seems to keep pace.

"They are probably trying to have a little race between them," Herrin wrote at the time.

Fluctuations in the twins' vital signs have also remained remarkably similar.

Since birth, the blonde, blue-eyed girls from North Salt Lake have shared a liver, kidney, bladders and a single pelvis. They had only two legs, each one controlled by one girl.

A team of six surgeons separated their torsos, liver, bladders and pelvis, leaving each girl with one leg.

Kendra kept the kidney, and Maliyah has been placed on dialysis. In the months ahead, she is expected to get a kidney transplanted from their mother, Erin Herrin.