“They’re just like their peers,” says Darla Keller, the mother of her triplets, two of whom are former twins.

Like most high school seniors, triplets Mackenzie, Macey and Madeline Garrison enjoy hanging out with their friends when they’re not working outside of school hours.

They enjoy horseback riding, climbing trees and spending time with their many pets in their Iowa home.

In almost every sense of the word, they’re typical teenagers – except that Mackenzie and Macey have been spouses in the past.

Whichever way they look at it, the girls are certainly extraordinary. Macey and Mackenzie were born joined at the pelvis and were separated ten months later by Dr. James Stein, Chief Medical Officer at Children’s Hospital Los Angeles, during a 24-hour surgical procedure in 2003.

Shortly afterwards, they were adopted by Darla Keller, now 50, who brought them back to Iowa with her three biological sons. Although the operation was successful, both girls have only one leg and must rely on prostheses to get around.

“Hardly a week goes by when I don’t think of them in some way,” says Mrs Stein. “I remember seeing them walk through the halls on their crutches, and seeing them ride horses and lead as normal a life as possible is really, really exciting.”

Although the triplets, now aged 17, have experienced other medical ordeals over the years (including spinal infusions for Macey and Mackenzie), they say their lives are as normal as can be, and look forward to graduating from high school and entering university.

Mackenzie isn’t sure what her future plans are, but she loves farming and plant anatomy, while Macey is considering becoming a kindergarten teacher.

Madeline, meanwhile, wants to become a nurse and, eventually, a nurse practitioner, with the aim of helping geriatric patients with Alzheimer’s and Parkinson’s disease.

“I think there are factors linked to the way I grew up and the people I’ve surrounded myself with who are very medically inclined,” she explains, noting that her mother is a physiotherapist.

Although the girls haven’t seen Dr. Stein in a decade, they keep in touch with the man who helped save their lives. Mackenzie and Madeline – who calls him “the coolest person ever” – recently e-mailed him to ask about his work and family.

“It’s been a wonderful experience keeping up with the girls themselves and staying in touch with them,” says Stein, who adds that they often find each other on social media. “But more recently, receiving letters from the children, as we have done on and off, has been very rewarding in that sense too.

Although the triplets have been making national headlines since their birth, the fact that the country knows all about their story comes as a surprise to the girls, who say they have learned to live with their disabilities and don’t see themselves as different from their peers.

“I don’t want people to know us at our school as the girls with one leg who are famous because of their story,” says Macey, “I just want to be myself, go out in public and make new friends. I’ll share my life story, I don’t mind doing it, but I don’t want it to become a huge thing.”

For Darla, seeing her daughters become the young women she calls her best friends has been a weight off her shoulders.

“I’m relieved because, like I said, we always knew there would be problems down the road,” she says. “I didn’t know exactly what they were going to be, but it’s a relief to see how normal they are. They’re just like their mates.”