You're most famous for your series of Horrid Henry books, which are beloved all over the world. Can you tell us how you came up with Henry to start with?
I got the idea by accident. I was chatting on the phone to an illustrator friend, who said she was fed up with drawing charming, happy children, and would I write a story about a horrid child. "Henry was horrid. Everyone thought so, even his mother," I replied which is, in fact, how the first book begins. So you could say that Henry was born on the spot.
I immediately saw an aggressive, impulsive, wilful boy, the despair of his well-meaning but biased parents. I was also interested in writing about sibling rivalry and families where the parents have decided that one child is good and the other bad, which is how Perfect Peter was born.
And how do you carry on coming up with ideas for Henry? Where do you find your inspiration?
Ideas are everywhere. I just think about ordinary family life and ask myself what Henry would do. I also keep an extensive 'ideas' notebook.
Your son Joshua is all grown up now, but did you enjoy reading to him when he was little? What sort of books did he like?
I LOVED reading to him and, in fact, read to him until he was 12 and he literally pushed me out of his bedroom! My husband also loved reading to him, so he did the morning shift and I did the evening one. It was a brilliant chance to catch up on some books I'd missed as a child. We really enjoyed The Hobbit, Little House on the Prairie, Tom's Midnight Garden, all of Roald Dahl, CS Lewis and Philip Pullman's His Dark Materials.
You're judging a competition with Charlie and Lola author Lauren Child to find the UK's Storytelling Suoerstar. What are you hoping to see from the entries?
Enthusiasm, fun, sparkle and the sheer enjoyment of sharing a story.
And are you a natural storyteller yourself? How do you bring stories to life when reading to children?
If you mean can I make up stories on the spot, absolutely not – in fact, I am awful! But I have learned to read out loud well by losing self-consciousness and by reading with attention and awareness of my audience. I also like to pause and bring the listener in, perhaps by asking a question or just with a silly aside.
Do you keep up to date with what other authors are writing for children and is there anyone you particularly admire?
I love reading children's books. I have just read Philip Reeve's Goblins, Sally Gardner's Maggot Moon and Steven Butler's fabulous The Wrong Pong; three authors whose work I love. I also think John Doughtery's Zeus On The Loose is hilarious.
What did you like to read yourself as a child?
I read for around six hours every day, so would get through about 10 books a week. My favourite book was Edward Eager's Half Magic, about a group of ordinary children who find a magic coin which grants them half their wish.
Finally, a friend's daughter – Ruby, who is nine and from Cheltenham – has a burning question for you: "Do you come up with all the jokes in the Horrid Henry joke books yourself (because they are the funniest jokes ever!)?"
I have help now – I don't know that many jokes!
If you love reading to your own children or grandchildren, might you be this year's Storytelling Superstar? There's still time to enter the competition, which Francesca is judging along with Lauren Child. Visit the World Book Day website for more details of how to upload your video.