A moving video showing the remarkable bond between an autistic girl and the cat that brought her out of her shell has been touching the hearts of thousands of people online.

Six-year-old Iris Grace Halmshaw of Market Harborough, Leicestershire, was once afraid of water but can now be seen swimming alongside her feline friend who helped her overcome her fears.

Not only do the inseparable pair practise their skills together in a swimming pool, they also share a soak at bath time - an everyday event that once filled Iris's mother with dread as just one drop of water could leave her daughter terrified.

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Iris Grace Halmshaw is severely autistic but her Maine coon cat Thula has helped her find confidence

Despite cats being known for their dislike for water, Thula joins Iris as she practices her swimming

As can be seen in the video, they do everything together with the cat sitting beside her in the garden as she looks at books and joining the family on canal boat trips, bike rides and walks on a lead.

And since Iris's parents bought the Maine coon cat for their daughter two years ago she has started to speak - something doctors warned may never happen.

Before her parents brought the moggy home, Iris was already an internationally acclaimed artist so talented that her work can sell for as much as £1,500 and had a huge following.

The home-educated youngster has been producing astonishing Monet-style landscapes since she was three, when mother Arabella Carter-Johnson devised art sessions to help her with her daughter's concentration and speech.

It was her fans online - mainly in America - who encouraged Arabella to look into getting a Maine coon cat to keep Iris company and help her to open up further, after equine therapy failed to help.

And as well as keeping a lookout for her masterpieces, the young artist's online followers now love to hear about her adventures with Thula, who has become a big influence in her artwork.

Bath time was once a trauma for Iris as she was afraid of water, but is happier now Thula joins her for a soak

Iris's mother Arabella said her daughter and Thula were inseparable from the day they bought the kitten home

The cat joins Iris on a variety of activities, from cycling and walks to days spent on a canal barge

Iris's astonishing tale of talent and relationship with Thula is lovingly told by her mother Arabella in a book released last month.

In it, she says that Iris and Thula were already like old friends from the moment they brought the kitten, named after one of Iris's favourite African lullabies, home.

She wrote: 'Thula was at Iris’s side from the moment she saw her and slept in her arms during her first night like a guardian angel.

'When Iris was looking at her books, she would delicately feel Thula’s ears and her long whiskers, or hold her tail at the tip, casually twiddling with the fur as if it were her own.'

Soon after, Arabella says Iris Grace seemed to have developed a spring in her step and started to communicate.

Thula is also a big influence in Iris's acclaimed artwork which can fetch anything up to £1,500 a time

Arabella said that from a very early stage, Thula would sit beside her daughter and mimic her movements

‘"Sit, cat," she would say when Thula was trying to play on her iPad. She said it with such authority that the kitten immediately sat,' Arabella explained.

'Unlike most children of Iris’s age would, she didn’t maul, stroke or pick up the kitten constantly. Their relationship was based upon companionship. Thula watched with great interest as Iris played, joining in whenever she could.

'When Iris stood at her table playing with play dough, Thula sat beside her, mimicking Iris’s movements.

She has proved to be the perfect companion for Iris, who is now much more confident and communicative despite doctors warning she may never speak

Thula also knows how to comfort Iris if she wakes in the night, and brings her a toy to help settle her

'I couldn’t believe what I was seeing: this tiny kitten was implementing the basics of play therapy.

'The more I thought about it, the more I could see what a perfect companion a cat was for a child on the spectrum.

'They understood one another in a way that we would always struggle to. There was an undeniable bond between them – a powerful connection that we had been searching for all this time.

'If Iris woke at night, Thula was there to settle her. It was as though she instinctively knew what to do. She would bring Iris a small toy in her mouth and drop it beside her.

Thula and Iris's touching friendship is documented in a book written by Arabella, which also tells the story of how art helped unlock her daughter's world

'Iris would play for a while with the toy and the movement in her fingers seemed to calm her.

'Thula would then snuggle up beside her and purr, while Iris gently settled and fell back to sleep. I would watch them from the doorway.'

Arabella told BBC Breakfast on Sunday: 'When we got the diagnosis for autism the doctors were quite depressing in what they thought was possible.

Just having Thula sit on Iris's lap calms her down and puts her at ease when she becomes stressed

Arabella says, to her, autism is 'brilliant' and doesn't need to be the grim diagnosis some people fear

'She was severely autistic and they said she may never talk. She may never be able to develop the relationships that other children can have.

'And then we got Thula and everything changed, there was a remarkable difference. She was able to communicate with us about what she wanted, it started with "more cat" and "sick cat" - she was giving her instructions.

'We've got this saying that different is brilliant and I really mean it - autism to me now is brilliant.

'It doesn't have to be this grim diagnosis. It can be challenging - very, very challenging at times - but I feel that if you work with the child and work with their interests you will see a progression, you'll see changes.'