The baby boys were connected at the pelvis and lower spine, facing away from each other.
Adrienne Spates' sons, Joshua and Jacob, are one of only two dozen successfully separated conjoined twins in the world and the first at a Memphis, Tenn., hospital.
On Aug. 28, doctors separated the babies during 13 hours of surgery.
Doctors say the biggest challenge was separating part of the spinal cord they shared.
"One of the huge successes here is not only are the boys healthy, but both of them are using their legs and getting ready to try to crawl out of bed," said surgical team leader Dr. Max Langham.
The boys were diagnosed prenatally at 25 weeks. The hospital intentionally delivered them at 34 weeks.
The timing was critical. If the babies weren't separated, Jacob, who had a heart defect, could not have it corrected.
"We didn't want to wait so long that that we created a high risk for Jacob, but we didn't want to go so soon that it would decrease the risk of success for both of the babies," Langham said.
Doctors say with a lot of rehabilitation, Joshua and Jacob have a chance at nearly normal lives.
"I think Joshua is actually going to be a low-level lumbar patient and is probably going to be able to walk with braces and be able to walk fairly well," Dr. Bob Wallace said. "Jacob has some other issues, but we hope that he'll be able to walk with braces and stand."
Officials at the Memphis hospital say it was the most complex procedure in the hospital's 59-year history. Doctors say they practiced on Cabbage Patch Kids dolls on how to turn and flip the twins without tangling all the lines attached to them during the long operation.