When Kendra and Maliyah Herrin were born, the doctors said it was unlikely they would live longer than 24 hours.

Those twin girls, who were co-joined, not only made it past 24 hours, they are now teenagers. When they reached the age of four, they were successfully ‘cut in half’ and now they live happily with only one leg each.

The sisters shared a single abdomen, kidney, pelvis, liver and large intestine. They are being featured in Living Differently, a BBC Three documentary. It discusses details about the 26-hour operation that separated the girls.

You can learn more about it what it is like to be Kendra and Maliyah in this video:

The twins were born in Salt Lake City, Utah and it took quite a few years before the parents, Jake and Erin agreed to have them surgically separated. Surgeons had not yet ever separated twins that shared a single kidney and it took months of careful planning and research before the operation could take place.

There was a significant amount of risk associated with the operation and doctors told the parents that if it went well, they would live a longer life and have a greater chance of independence. Failure could mean death to both girls.

We’re happy to say that the unprecedented separation surgery was a success. The surgery itself lasted more than 24 hours and it went smoothly enough that they were out of the hospital within six weeks.

The girls have had to endure some medical issues, such as living with a single leg each and having spine straightening procedures.

Kendra received the single kidney that was shared between the twins and Maliyah has had multiple kidney transplants.

Maliyah was only five years old when she received her first kidney and it came from her mother. She was able to keep that kidney for 10 years but it began to fail when she was 15. She went on dialysis received one from an anonymous donor about 18 months later.

Even though they are part of such an interesting medical procedure, they will tell you that they are just normal teenagers.

“When people first hear our story, they like to ask a lot of questions,” Kendra said in the BBC Three documentary. “But simply we feel like we’re the same as everybody else, we just have a few things that are a little different.”

Maliyah added: “Our parents talked to us about ‘cut apart day,’ but we were so young we didn’t really understand what was happening.”

The girls still have a rod in their backs because they suffer from scoliosis but they are able to attend school, hang out with family and do chores. They also have their own blog and a big online following.

The girls are happy that the parents decided to go through with the surgery and are doing well, even though the circumstances are less than ideal.

“The best thing about only having one leg is we only have to paint one set of toenails,” Kendra joked.