A 10-year-old girl swam 5 kilometres in a bid to help her school friend raise enough money to get an assistance dog.

Sophia Hill took on the mammoth challenge with her dad at The Quays, raising more than £1,500.

Starting just after 6am, she completed the challenge in just over two hours.

She was moved to take on the trial to help her friend Lily Peacock get an assistance dog.

Lily lives with Wiedermann-Steiner Syndrome, an extremely rare genetic condition that only affects 2,00 people in the world.

“Essentially it’s a genetic change which means Lily is affected globally,” said Lily’s mum, Alex Peacock.

“She has relatively significant learning difficulties, she’s got bone abnormality, she is pretty much bowel incontinent, a lot of dental issues. But having a super rare conditions it means there’s not often examples so you’re wondering what’s coming next for Lily.”

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Sophia built up her stamina by training with the City of Southampton Swimming Club, and head coach Matt Heathcock, 42, called her ‘an inspiration’ for going the distance.

Matt said: “Our club is driven and determined and Sophia showed that today, from her age, I think it’s amazing.

“For a young girl to swim 5,000 metres at six in the morning, and in fact from a coaching point, she did it technically well. I think she’s an inspiration and shows what our swim family is about.”

Sophia was cheered on by her family and Lily's mum Alex Peacock.Sophia was cheered on by her family and Lily's mum Alex Peacock. (Image: Newsquest) Sophia said that she had "really bad cramp" at one point and did not know if she would be able to finish the swim, but she pushed through and went for a well-deserved ice cream breakfast afterwards.

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“She’s already a lovely sweet girl and a great friend to Lily, but to see how dedicated she was to do something like this, it’s amazing,” Lily’s mum Alex said.

Speaking of the importance of an assistance dog, Alex added: “As Lily’s getting older, friendships are harder because she doesn’t engage typically. It’s harder for her to hold relationships but she’s so socially driven and she wants friends, so the dog will be a pal for her.

“She has bad anxiety so leaving the house, she’s always anxious, so with a dog she gets to take a bit of home with her.

“Even going to the local shop, at the moment there’s no chance she’ll ever be able to do that, but I think with a dog, that would be enough to make her comfortable enough to do it."