Millie-Anne Hemley suffered horrendous injuries after being attacked by her pet Staffordshire bull terrier, called Rory.
Millie-Anne's injuries were so horrific that doctors told her mum, Paula Warren, 32, they would have to amputate.
Paula said: "They said if she was left with that bit of her leg, the foot would be useless. But I was just hearing, 'we're going to cut her leg off'.
"It must have been the slowest I have signed my signature ever."
Incredibly, though, just a month after the ordeal, Millie-Anne is bright and cheery as she balances on her crutches.
She said: "Everyone calls me a little soldier and everyone says I'm brave. I don't feel brave, I just get on with it and keep smiling."
Milly-Anne recalled how Rory grabbed her leg when she screamed as he tried to bolt through an open front door.
She said: "He just didn't let go and he shook me. "I remember my whole body shaking, I was hugging his back and saying, 'it's only me, Rory'.
"My brother pushed him against the stairs and got him off me. He came at me again and bit my other leg, but they pushed me into the living room and shut the door."
Milly-Anne was left with just skin and bone holding her right shin together and surgeons fought to save the limb. But just two hours later they asked mum Paula Warren to give permission to amputate.
Milly-Anne spent Christmas in hospital after losing her leg at the shin on December 19 and has been learning to walk on crutches. She will be fitted with a prosthetic after her leg has healed.
Paula, from Long Buckby, Northants, was working during the attack and had left the eldest of her four children, Braydon, 15, in charge.
She said: "I blame myself entirely because I'm a mother and I wasn't there. When I got home it was so horrendous. It was just gone, it was just a piece of bone.
"I watched her leg turn from pink to blue to white, you could see there was no blood getting there."
Rory was put down but Paula told how he had never shown signs of aggression.
She added: "This proves that you just don't know your own dog - we don't know why he did it, we'll never know."