Formerly conjoined twin girls Adeline and Knatalye Mata were wheeled into an operating room at Texas Children’s Hospital one year ago today to undergo a highly complicated and risky surgery to separate them.

They were just 10 months old at the time and had spent their entire young lives living face-to-face. They shared a chest wall, diaphragm, intestines, lungs and lining of the heart and pelvis. Their chance of surviving the long surgery was still an unknown at the time.

But now it’s been one year since the surgery and the twins, whose middle names are Faith and Hope, are continuing to beat the odds. Both girls are thriving and will celebrate their 2nd birthdays on April 11.

“The girls are both doing so well,” Dr. Darrell Cass, the lead surgeon on the case and co-director of Texas Children’s Fetal Center, said in a statement. “Neither have experienced any complications and they are both making steady progress.”

The girls’ mother Elysse Mata said in an interview provided by the hospital that both girls have reached different developmental milestones and are growing into their own personalities.

“Knatayle is trying to walk,” the girls’ father Eric Mata added. “She knocked out crawling so now she’s trying to walk.”

“Addie can’t walk or crawl, we’re working on that,” Mata continued. “But she scoots and she’s also all over the place too."

“Nightline” was at Texas Children’s Hospital last year as a team of 12 surgeons spent 26 hours performing the separation surgery on Knatalye and Adeline.

Since the surgery, the girls have continued to come to the hospital for procedures and follow-up appointments.

Dr. Cass said the next step will be for Knatalye to undergo an operation on her chest again “to remove the metal struts that were used to stabilize the rib cage and to formally close her chest wall.”

While Adeline’s lungs are improving, Cass said she is still on a ventilator, but they are working on weaning her off it, and she will continue to work on speech and physical therapy.

“A year ago, we were up almost 48 hours and we didn’t know what was going to happen,” Elysse Mata said. “So to be able to look back on that and think, ‘Wow, here they are’ … it’s exciting. You look at them and you wouldn’t know that a year ago they were lying on a hospital bed facing each other, miserable because that’s all they could do, and I’m just excited about the next years.”