As the best-known conjoined twins in recent history, Abby and Brittany Hensel have consistently challenged our expectations regarding their capabilities.

Yet, perhaps nothing has sparked as much astonishment – and a sense of happiness among their numerous fans – as the image that surfaced last month, depicting them placing a baby in a car seat into the back of a black Tesla in a parking lot in Arden Hills, Minnesota, located just ten miles from Minneapolis.

In the following weeks, the twins have been spotted on several occasions holding the baby seat, including one instance where they were seen conversing with a colleague outside the school – Sunnyside Elementary in New Brighton – where they are now educators.

The sightings have inevitably sparked intense speculation about the 35-year-old sisters’ lives.

Last year, the twins, who generally lead a life away from public attention, made news when it was revealed that Abby had quietly married nurse and US Army veteran Joshua Bowling three years prior, in 2021.

It was an arrangement that left many scratching their heads over just how such a relationship works.

In a television documentary series from 2003 titled ‘Joined for Life,’ the twins had expressed a desire to someday have children, though neither they nor Bowling have made any statements regarding whether this child is theirs.

However, medically, it is entirely possible.

Abby and Brittany are dicephalic parapagus twins – a rare form of conjoined twins in which they have two heads but share one body.

Though externally they appear to share one body, they have their own separate upper body systems including two hearts, two stomachs, two pairs of lungs and two spinal cords.

Yet each heart pumps blood through the same circulation system and they have a single liver and large intestine.

Similarly, they share organs below the waist, including a single reproductive system.

Although they are remarkably symmetric for conjoined twins, there are some inconsistencies in their physiology. They share three kidneys and originally shared three arms.

A rudimentary central arm was surgically removed shortly after their birth, leaving only an extra shoulder blade to which it was attached between their necks.

Because their brains and spinal cords function separately, coordinating movements for their respective sides of the body, Abby controls their right arm and leg while Brittany does the same on the left.

Brittany’s leg is nearly two inches shorter than Abby’s so she tends to have to stand and walk on tiptoe so they can maintain their balance.

Conceiving and giving birth sounds like a considerable challenge – until one understands what they’ve already had to share together and the compromises they’ve been prepared to make.

After all, dicephalic parapagus twins rarely survive into adulthood, let alone enjoy rich lives with careers, marriage and children.

They were born in 1990 in Carver County, Minnesota, to parents Patty, a nurse, and Mike Hensel, a carpenter and landscaper, who had no idea they were expecting twins.

Doctors later claimed the girls’ heads must have been perfectly aligned during ultrasounds to conceal the fact that there were two of them.

At the birth, the twins’ heads came out last. ‘We all stood in silence for about 30 seconds,’ recalled Dr Joy Westerdahl, the family’s doctor, who assisted at the birth. ‘It was extremely silent.’

More shocks followed, when the parents were told by doctors that the twins might only survive for a few hours.

However, the Hensels decided against a surgical separation after being advised that it was likely that one baby would die while the other would be left with a single arm and leg and be confined to a wheelchair.

The parents have said they never regretted their decision because Abby and Brittany thrived together.

Patty later said: ‘From the first time we saw them, we thought they were beautiful.’

And speaking in 2001 her husband Mike further explained why they never chose to separate their daughters asking: ‘How could you pick between the two?’

Their condition was so rare that doctors were surprised to discover that each twin controlled one side of their body and was unable to feel the other side.

However, a curious exception is stomach aches which are felt only by the twin on the opposite side.

And yet, despite so many complications, babies they learned to synchronize their movements so that they could crawl and clap.

Doctors were again dumbfounded when the little girls proved able to walk instinctively and without having to talk to each other to discuss coordination.

They can eat and write separately and simultaneously. They later added playing the piano, swimming and volleyball to their skills.

Other children struggled to cope with the concept that they were two separate people, but their parents never had the same problem and disciplined them individually.

The twins first came to national attention in 1996 when, aged five, they appeared on the Oprah Winfrey Show.

That same month they were featured on the cover of Life magazine under the headline, ‘One Body, Two Souls.’

However, the family has always had an ambivalent relationship with public attention and, for the most part, the twins grew up quietly in their tiny hometown of New Germany, Minnesota.

The young twins, who had radically different ambitions in life – Abby wanted to be a dentist, Brittany a pilot – reportedly only once raised the sensitive subject of being separated.

The matter came up when the girls were 12 and Brittany fell ill with pneumonia, a condition which put Abby’s health at severe risk and saw them hospitalized.

Abby remained healthy but got bored lying in bed and suggested separation. She later said she saw that Brittany was so upset she promised herself that she would never talk about it again.

In 2003, they appeared in the documentary, ‘Joined For Life,’ in which their mother revealed they were interested in having children one day, saying: ‘That is probably something that could work because those organs do work for them.’

Brittany concurred, saying: ‘Yeah, we’re going to be moms. We haven’t thought about how being moms is going to work yet. But we’re just 16 — we don’t need to think about that right now.’

Then, in 2012, the twins returned with their own eight-episode reality TV series, ‘Abby & Brittany,’ on TLC.

They were 22 and truly inspiring – surrounded by a gaggle of supportive friends and about to graduate from Minnesota’s Bethel University with degrees in education.

Their parents had raised them to believe they could do anything they wanted to.

Endlessly giggly and finishing each other’s sentences, they were clearly very different personalities.

Abby was more stubborn and outspoken while Brittany was the wise-cracking, easy-going ‘homebody,’ who rarely won discussions about what they’d wear each day.

Brittany preferred rural life, Abby the city. Yet, just like when they’d been children, they rarely argued and when one had an itch, the other would obligingly scratch it for her.

By 2012, they had learnt to drive – each taking a separate test and receiving their own license.

‘Abby does the pedals and the gear shifter, I take the blinkers and the lights, we both steer,’ explained Brittany. ‘But she likes driving faster than me.’

Teaching fifth-grade math at school – where they shared a salary – posed another intriguing challenge but they had at least one advantage over a teacher with only one pair of eyes.

Brittany said: ‘One can be teaching and one can be monitoring and answering questions…so in that sense we can do more than one person.’

Although they came across on TV as eternally optimistic, being conjoined twins certainly has its downsides.

Unsurprisingly, they hate gawkers staring at them. But that hasn’t put the plucky pair off traveling. They’ve been to Europe and the UK several times and reportedly even did a teacher training stint in London.

They are always on guard for people trying to sneak pictures of them and resent being asked intrusive questions about their private lives.

When Abby married Bowling, she did so in a ceremony so small and private that the media didn’t find out about it for three years.

It still isn’t known how the twins met the former army medic who served in Iraq, Kuwait and Afghanistan and has a daughter, Isabella, from a previous marriage.

The twins’ ability to wring every possibility out of life is astonishing and it’s clear that their parents have fed that positive outlook.

In 1996, when asked in an interview with Life magazine if his girls might one day find husbands, their father Mike said he saw no reason why not.

‘They’re good-looking girls. They’re witty,’ he said. ‘They’ve got everything going for them, except…’ and he paused…’they’re together.’

Nearly 30 years later, they’re still together and, with the arrival of a baby, seem to be embarking on the next exciting chapter of their extraordinary lives.