A team at Texas Children's Hospital separated Knatalye and her sister, Adeline Faith, on Feb. 17 in a 26-hour surgery. They celebrated their first birthday in the hospital last month, with a "Frozen"-themed party.
The two had both been in the pediatric intensive care unit since their surgery and have each had a few surgeries since the separation, but doctors decided Friday that Knatalye was strong enough to be released.
The girls' mother, Elysse Mata, was shocked to learn the twins were conjoined when she was pregnant with them, she told ABC News in July.
"I was speechless, it was so unexpected," she said.
Their middle names are Hope and Faith because you can't have one without the other, she said.
The girls were born on April 11, 2014 at Texas Children's Hospital. They shared a chest wall, diaphragm, intestines, lungs, lining of the heart and pelvis.
"Nightline" was at the hospital in February as 12 surgeons operated on the Mata twins, and Elysse, her husband and 20 family members camped out in the waiting room.