Her books are based on her own magical East Anglian childhood. Now Sheridan Winn is watching them come to life on a film set

Norwich Evening News: Sheridan Winn and her daughter Rosie at MONEV Studios, BrusselsPhoto: Andreas GutzeitSheridan Winn and her daughter Rosie at MONEV Studios, BrusselsPhoto: Andreas Gutzeit (Image: Photo: Andreas Gutzeit)

Sheridan Winn's Sprite Sisters stories are set in Norfolk, hugely popular in Germany and about to be made into a film distributed by Disney.

Sheridan, of Bergh Apton, near Loddon, has written seven Sprite Sisters books, which have struck a particular chord with little girls in Germany, selling more than half a million copies.

She grew up in Drayton, near Norwich, running wild in an overgrown garden with ponies, dogs, cats, rabbits, chickens, a pig, and at one point 63 guinea pigs. She went on to study graphic design and helped her ex-husband produce picture books based on the exploits of their two children.

And now her Sprite Sisters, who sprang from her Norfolk childhood, are about to become film stars.

Norwich Evening News: The Sprite Sisters and Mrs DuggeryFrom left:Laila Padotzke/actor Flame; Lilith Julie Johna/actor Flora (Ash); Leonore von Berg/actor Sky (Ariel); Hedda Erlebach/Marina with Mrs Duggery behind (Anna Thalbach)Picture: BVI/blue eyes/Marco NagelThe Sprite Sisters and Mrs DuggeryFrom left:Laila Padotzke/actor Flame; Lilith Julie Johna/actor Flora (Ash); Leonore von Berg/actor Sky (Ariel); Hedda Erlebach/Marina with Mrs Duggery behind (Anna Thalbach)Picture: BVI/blue eyes/Marco Nagel (Image: Picture: BVI/blue eyes/Marco Nagel)

It started with nine words – four girls with magic powers. East. South. West. North – written in my diary at 1.30am on January 21, 2007, in Norwich.

The following morning, the idea for the Sprite Sisters – who have the magic powers of Fire, Water, Earth and Air – was born and I mailed Brenda Gardner, owner of children's publisher, Piccadilly Press. She liked the idea of four sisters, four elements, four powers. In May, I had a contract. It happened as if by magic.

Eleven years and 14 books later, I am at the MONEV Studios in Brussels watching a key scene of the Sprite Sisters film.

Norwich Evening News: The Compass Rose Room. From left: Andreas Gutzeit/Story House; Leonore von Berg/Sky; Lilith Julie Johna/Flora; Corinna Mehner/Blue Eyes Fiction; Sheridan Winn/author; Laila Padotzke/Flame; Andreas Peschel-Mehner/Blue Eyes Fiction; Hedda Erlebach/Marina; Hortense Ullrich/screenwriterPicture: BVI/Blue Eyes Fiction/Joe VoetsThe Compass Rose Room. From left: Andreas Gutzeit/Story House; Leonore von Berg/Sky; Lilith Julie Johna/Flora; Corinna Mehner/Blue Eyes Fiction; Sheridan Winn/author; Laila Padotzke/Flame; Andreas Peschel-Mehner/Blue Eyes Fiction; Hedda Erlebach/Marina; Hortense Ullrich/screenwriterPicture: BVI/Blue Eyes Fiction/Joe Voets (Image: Picture: BVI/Blue Eyes Fiction/Joe Voets)

Disney Germany will be the film's distributor.

It is a surreal experience to meet my characters in person. Until now, Flame, Marina, Ash and Ariel have been in my head. Now they are played by actors who look, almost, but not quite, like the characters I imagined. It is also strange to think so many people – the film crew of 70, the cast of actors, the production and post-production teams – are involved in the process. Writing is a solitary process. Film requires big teams of talented, committed people, who are all here because of my nine words. I have dreamed it up and am now letting it go. The Sprite Sisters are moving to a new dimension.

It was in December 2013 that Andreas Gutzeit called to ask if his company, Story House, could option the film rights to the Sprite Sisters. By that time my books (which were set in Norfolk and very English in tone), were well-known in Germany. For several years, Gutzeit worked on selling the Sprites as an English-language drama series but it did not take off. Then he changed to film and focused on the German market, where the Sprite books had sold over half a million copies.

There were 500 girls at the casting: the Sprite Sisters need to be able to sing and dance as well as act.

The 39-day shoot for the 100-minute film is in locations in Germany, Austria, Belgium and South Tyrol. Today I am watching Scene 18, the 'Compass Rose Room' – in which the Sprite Sisters find the source of their magic power, deep in the cellar of Sprite Towers. I sit in a vast studio. In front of me is the plywood set raised on a platform a metre off the ground. From outside it is a series of odd shapes. Inside, it is a magical space, in the middle of which is the compass, set into the cellar floor. This device shows the directions of East, South, West and North, and lights up, turns around. From the centre a rose arises, affirming the Sprite magic is alive.

Headphones on, I watch the video screens that show the shots the camera lines up. Film is a concentrated process: for every minute used in the final cut, 30 minutes will have been shot.

The theme of the Sprite stories is balance. If the four sisters work together, their magic is strong. If they argue their power weakens and they may lose Sprite Towers. Everything has to come back to the balance. As the eldest of four sisters, I can hear the Sprites' conversations in my sleep. Writing the stories has been a natural experience in which I have evoked memories of my Norfolk childhood. The film is being billed as 'a family comedy' – and that's fine by me.

Vier zauberhafte Schwestern, which translates as Four Magical Sisters premieres in Munich in January 2020. I shall have to buy a dress . . .