Rhiannon Jones thought somebody was spinning her a yarn when she found out she had won a national competition. ‘I was told in late April and thought it was a late April Fool’s joke,’ said 11-year-old Rhiannon, who was one of four winners out of about 9,000 youngsters who took part.

The St Martin’s Primary School pupil had entered the Times Educational Supplement Write Away competition.

She went to the Globe Theatre in London on Thursday to collect her prize.

Children’s authors Jacqueline Wilson and Michael Rosen judged the shortlist of candidates and selected as a winner Rhiannon’s short story, In My Mind’s Eye, which tells of an imaginary friend her speaker concocts called Diana.

‘I made her sort of the opposite of me.

‘She does not have big feet like me – I’ve got whopping great big feet.

‘And she is good at maths – and I’m terrible at maths,’ said Rhiannon.

Diana is an imaginary replacement for a best friend who, Rhiannon said, had deserted the speaker for a new girl in class.

In making friends with Diana, she becomes best friends with herself and finds hope.

Rhiannon’s win comes in the same year that she was awarded a scholarship to Ladies’ College through the 11-plus exam, and won the Cooper Brouard and the Fairtrade design-an-ad competitions.

‘It’s been a lucky year for me,’ she said.

St Martin’s head teacher Cate Mason said her pupil’s achievement had been well deserved.

‘We are very proud of her. She has always been a very able student who has had a great passion for writing.

‘She works very hard at her writing but she also has a natural talent, which has been nurtured through her work with her English teacher, Liz Mahy.’

Rhiannon said she wanted to pursue the craft and was writing another story.

‘I want to be a marine biologist and I would like to write children’s fiction part-time about the ocean.’

Rhiannon is the daughter of Emma and Gareth Jones.