Daisy had been undergoing physiotherapy for her back, which was twisted after the stroke left her right side paralysed.
She disliked the repetitive exercises, but riding 24-year-old Dollar – holding the reins with her left hand – proved to be the perfect therapy.
By the age of five, her back muscles were strong enough to allow her to walk short distances.
Mrs Pritchard, from Wrexham, Wales, gave birth to Daisy in 2006 after she and husband David, a company director, had several rounds of IVF.
Tests in 2008 revealed Daisy had only three heart chambers instead of the normal four and needed an operation to reposition her arteries.
The first surgery went wrong and she was rushed back for a second operation, during which she had the stroke.
Her mother said: ‘When Daisy had gone into theatre she’d been a beautiful, blonde, chatty toddler who was running around. Now she was just lying there helpless.’
Since learning to ride, Daisy has come on in leaps and bounds – walking, talking and attending mainstream school – although she still uses a scooter or wheelchair to help her get around outside the house.
She can ride without any assistance and has even developed a special way of communicating with Dollar, tapping either side of his neck to ask him to turn.
Mrs Pritchard, said: ‘Without Dollar in her life I don’t believe Daisy would have ever recovered. He became her legs, her reason to get up and walk.
‘It might sound strange to say about a horse, but I will always be so grateful to Dollar … I thought I’d lost my beautiful daughter but his healing has brought her back.