Once upon a time Iona Rangeley should have been studying for her university finals. Instead she began writing a story about a penguin.

And soon there was a happy ending – with the book published and Iona setting out on a career as a children’s author.

Iona, who grew up in Thornham on the north Norfolk coast was supposed to have been writing a dissertation on children’s literature and studying for her final exams in English literature at Oxford University but instead of revising the work of writers from the Renaissance to the 19th century and reading the plays of Ben Jonson and the poems of Wordsworth, she was inventing a penguin called Einstein.

She said writing Einstein the Penguin was definitely more fun than revision.

And alongside graduating she was also negotiating publishing deals. The story of a penguin who follows a family home from a day out at the zoo struck a chord with readers. It's been published by HarperCollins Children’s Books in hardback and paperback and named a Sunday Times Children’s Book of the week.

The audio book version was narrated by Miriam Margolyes and won a New York Radio Festival award.

The charming illustrations are by David Tazzyman and Iona said: “I really think David’s illustrations are perfect: even if things aren’t exactly how I imagined them, they’re usually better than I imagined them and actually change how I see my own book.”

The book tells the story of two children, Imogen and Arthur, who take Einstein in and help him find what he is looking for (while he helps them too.)

Described by the publisher as fantastically funny future classic, it is aimed at children aged seven to 10. “But younger kids can definitely have it read to them by parents, and there are illustrations every few pages,” said Iona. “I always write with parents as well as children in mind because I really love children’s books that can be enjoyed by all age groups, so really Einstein is for the whole family!"

Much of her own family are in Norfolk with her parents in Thornham, grandparents in Wells-next-the-Sea and her brother in Norwich.

Iona was just five when wrote her first story, Sam and the Pig, and grew up wanting to be an author.

This summer she returned to her old school, Gresham’s in Holt, to talk to some of the younger children and read extracts from Einstein the Penguin – and some of her childhood stories.

“I spoke to the children about my own experience of the school, as well as the importance of being creative and finding out what you love doing,” said Iona. “I always knew throughout my time at Gresham’s that I wanted to be a writer so going back there was definitely a full circle moment, and it’s really important to me to inspire children to believe in themselves and to go after the things they want to achieve.”

Iona went on to Magdalen College Oxford to study English literature and is now writing full-time – and enjoying giving talks to children. “I think it’s such an important part of being a children’s author because it means coming face-to-face with your own audience."

She said it took around 10 months from when she began writing the book to getting an agent to send it to publishers. "My agent sent it to lots of publishers at once, and there were obviously plenty of rejections but also some interest,” she said. “I ended up with three publishers interested.”

The Times called it “An outstanding debut. Funny and surprising,” and the Sunday Times said “Its wit and observation put it in the tradition of Eva Ibbotson and Hilary McKay. Full of unexpected phrases and illustrated with just the right degree of freedom and quirkiness, this is a real discovery. A joy to read aloud.”

Einstein the Penguin: The Case of the Fishy Detective picks up the penguin’s story a year later and is due out in October and Iona is already working on her third penguin adventure.

“I love writing for children and I have plenty more ideas for new books, so I’d definitely like to keep writing. I’d also like to write a book for adults at some stage,” she said.