The last time British author and illustrator Lucy Cousins, who has more than 30 million books in print worldwide, visited this side of the pond was to celebrate the 10th birthday of her most famous creation, Maisy. That was in 2000, just after Maisy debuted in her own TV series on Nick Jr. In the intervening years Maisy has been featured on U.S. postage stamps and starred in the “Read with Kids Challenge” sponsored by Reading Is Fundamental and US Airways. So when Cousins arrived for a brief visit earlier this month, PW jumped at the opportunity to catch up with her, at the Somerville, Mass., offices of her U.S. publisher, Candlewick Press. That was her penultimate stop on a tour that took her to several stores in New York City and the Greater Boston area. Her final stop was a visit to the Eric Carle Museum of Picture Book Art in Amherst, Mass., where an exhibit called “Our British Cousins: The Magical Art of Maisy and Friends” was on view.

How did you get interested in writing and illustrating children’s books?

My mum and dad are artists, and they both had studios at home. For as long as I can remember I always wanted to be an artist. I felt an affinity with small children at the age they haven’t been shaped or molded. I [studied] graphic design, and when you’re at the Royal College of Art, you get a free pass to the zoo. I’d been drawing lots and lots of penguins, and I wrote Portly’s Hat. [That picture book, Cousins’s first, came in second for the Macmillan Prize and was subsequently published in the U.S. by Dutton in 1998.]

Your next two books, Maisy Goes to Bed and Maisy Goes Swimming, featured the mouse for which you are best known. That was 22 years ago, but Maisy never seems to age. How old is Maisy?

I don’t think of her being an age. I think of her as being Maisy. I guess she’d be three. She hasn’t got parents. It’s just the way she is. When I was still at college, I wanted to do a book with flaps, and there was a girl in it. Wendy Boase at Walker said, “I think your animals are really good.’ When I drew this mouse, I knew who she was. I wanted her to be very cheerful, very positive. She doesn’t get worried about things. I want small children to feel good and enjoy the story.

Do you ever worry about running out of Maisy ideas?

I can’t believe my luck, really. I think, “I can’t think of another idea.” Then I do.

Obviously when the children [Cousins has four, including 16-year-old twin boys] were young, they gave me lots of inspiration. The books are pretty much about everyday things. After my sons’ third birthday, I thought, “I have to do a book on birthdays.”

Donna Cassanova, character publisher at Walker Books UK (sister publisher to Candlewick) describes working with you as “entirely collaborative.” At the beginning of your career, you used to stop by Walker’s offices frequently. How do you work together now that you’re a train ride away?

I’ve worked with the same two people for 15 years [Cassanova and David Lloyd]. When I’m working on a book, it’s like a puzzle. The story has to have a beginning, middle, and end. I have to decide how many pages and where the words are. I can get stuck. When I get to that position, every three to four weeks, I take a train to London and we sit down. That usually unlocks something, and they see it evolve right from the beginning.

How involved is your U.S. publisher in Maisy and your other books?

Candlewick gets involved with the cover design. Sometimes everybody disagrees about the cover. Sometimes we have a different cover in the U.S. and the U.K. The cover’s the hardest part. I want my illustrations to look spontaneous, like I just sat down on a nice sunny day; spontaneous and childlike.

Do you ever think of trying something different?

In small ways sometimes. In Create with Maisy I used photographs for the first time. In Doodle with Maisy [April 2013], I did it all with crayon instead of paint to feel like doodling.

I just finished a book with a new character that’s a woodpecker. It’s a similar style artistically. The woodpecker pecks holes, and the final page is full of holes. It was quite complicated to do the artwork so that the words don’t show through the holes. [Peck, Peck, Peck] will be out next summer.

Where do you work?

I have a room at the side of the house that’s my studio. I’m quite good at switching off from family to work. I like to work in short bursts. My brain can only really focus for a short time.