Kirstie Edelson from Leicestershire suffers from a disease called diastrophic dysplasia which inhibits proper bone growth.

She said her book, Knight Night, was inspired by another story called Indian in the Cupboard

"We had to write a story at school and my teachers decided it was good enough to publish," the 10-year-old author said.

Her mother Jane said: "Kirstie has always been a bookworm, and now her imagination has made it into print."

"It was gobsmacking really, the thought of having something by her in print is fantastic."

The proceeds from the book are being given to the Rainbow Children's Hospice.