Diamond (aka TwilightVi): When you were writing Emerald Star, when we first met Diamond, did you know you were going to write a book about Diamond?

No, I didn't. I thought Emerald Star would be the last book about Hetty. The publishers thought that too, because somewhere in Emerald Star it says, 'the third and final volume about Hetty Feather'. However, when I finished writing it, I started to think about Diamond, I thought she was a lovely character. I thought initially I could write just a little book about Diamond, but then I got into the story and thought: 'no, there is lots I want to write about Diamond,' so it became a huge long book.

Hetty (aka Lottie Longshanks): Did you have a strong picture in your mind of what Hetty looked like when you started writing your book ?

As soon as I knew I was going to write about a foundling girl, I felt she is going to be small, light as a feather and have bright red hair, make her distinctive. If you've got lots of little foundling girls all dressed the same, what would make somebody stand out? Red hair. In Victorian times, they didn't think red hair was particularly beautiful. I love red hair! But, for the Victorians, particularly if you were a servant, it was considered a disadvantage. So I thought, I'd give this poor little kid every disadvantage, but then she's got so much fighting spirit, she'll win through! I had this idea of her in my head, and then wonderfully for me, Nick Sharratt drew her exactly as I had imagined her.

Diamond: Do you tell Nick Sharratt what to draw or does he make it up?

Nick makes it all up himself. The very first book we worked on together was the story of Tracy Beaker and I didn't know who would be illustrating it, so I left lots of bossy instructions. Nick was very sweet and tried to do exactly as I indicated. As soon as I saw his art work, I knew he has much better ideas of how to illustrate than I can imagine it. So now, it's just a treat for me! I send him my manuscript and then I wait eagerly, and then he just sends me the illustrations and they are always absolutely perfect.

Hetty: What sources did you use to create Hetty Feather?

The best way to doing the research is actually to read Victorian novels, both for adults and children, written in that period. There's a Victorian novelist for children, Mrs Molesworth, who wrote lots of books about children. There's an adult author called George Gissing, and he wrote great, long stories, full of detail – about what people were wearing, what the streets looked like. So I could read these to get the feel of what it was like. Also, it helps have a vivid imagination.

Diamond: Do you relate to one of the characters you wrote about?

In a way, I relate to all of the characters as I'm writing their stories, because I get so close to them. I don't think I'm as spirited as Hetty, or as naughty as Tracy, or as greedy as Biscuit. But there are little bits of me in all the characters.

Hetty: Hetty did so many brave things. What do you think was the bravest thing she did?

I think the bravest thing was when, after her mother died, to be able to think: 'Well, I've still got to carry on, I've got to earn my own living, and how weird it must be to dress up as a mermaid for this very dubious freakshow at the seaside, just to be able to get some money!' I think she's a girl that, no matter what happens to her, she finds the spirit to fight back and keep her head. I feel quite proud of her, as if she's my daughter.

Diamond: I'm desperate to find out what Hetty and Diamond get up to. Are you going to write a sequel?

I think I am. There's a very strong hint at the end of Diamond, that they are going to have a whole new career, maybe on the musical stage. It is fun for me to find out what happens to them all. I think you are going to have to be a little bit patient though, because I am just finishing a long long Edwardian novel about a different girl entirely, then I'm going to write a short book for younger girls about triplets. After that I'm going to write a modern version of a classic favourite of mine, What Katy Did. That's going to keep me very busy all this year and a bit of next, but we'll find out what Hetty and Diamond are going to be doing after that.

Hetty: Do you think I have captured the spirit (even a little bit) of Hetty in my dress up today?

Absolutely! I think you've been very imaginative the way you've put it together. I think you both look absolutely splendid! And Diamond, in your fairy costume, it looks lovely!

Diamond: I'm your biggest fan!
Hetty: So am I!

Well, it's lovely that you're both my biggest fans! It's a big treat for me to see you both looking so wonderfully in character.

Fans of Hetty Feather and Jacqueline Wilson can see Hetty Feather live on stage in a brand new show playing at four venues: Kingston, Birmingham, Cheltenham and Edinburgh, running on various dates from 5 April until 31 May 2014. Find out more about dates and venues, and book tickets here Hetty Feather Live.

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