Megan McDonald had already published picture books when she met Candlewick editor Mary Lee Donovan at a writers’ conference in the summer of 1997 and asked her to read some (okay, maybe a lot of) stories McDonald had written about her adventures as the youngest of five sisters.

“I loved the character, the writing, the humor,” Donovan recalls, “but it was all anecdotes. There was no continuous arc.” Undeterred, Donovan agreed to work with McDonald until they hit upon the right structure.

That makes Donovan godmother to Judy Moody, who came into the world 17 years ago and has become one of Candlewick’s key properties, with more than 34 million copies in print (including spinoffs featuring Judy’s little brother, Stink).

All that time in third grade has earned Judy a makeover. Candlewick will relaunch the series next April with redesigned cover art that will swap out Judy’s trademark brown-paper-bag background for tiger stripes—a wink at the pajamas Judy wears to school after waking up late—and feature vibrant artwork the publisher hopes will put Judy’s personality front and center.

“We’re aiming to highlight the humorous, spunky, and confident little girl who readers have come to know and love,” says Veronica Wasserman, executive marketing director for the Walker/Candlewick Group. A new installment, Judy Moody and the Right Royal Tea Party, will release in September 2018, the 14th volume in a series that developed very organically.

“Originally, the impulse came from wanting to capture all the funny stories I had about growing up,” McDonald says. “I thought, ‘Could this be an easy reader?,’ because I had all these separate vignettes about the moon rock, and the Toad Pee Club, and the fake hand, but I didn’t know what to do with them. Mary Lee is the one who found a connecting thread in all the material and suggested a short chapter book.”

The solution Donovan devised was to have the first book’s plot mirror Judy’s school assignment. “Because Judy was making a ‘me collage’ for school—here’s my family, here’re my pets—that gave Megan permission to write a book that was a bit of a collage itself, an introduction to the character.”

McDonald gave Judy a brother “to put some distance between the real-life story and my fiction,” she said. And she made Judy the oldest, not the youngest, as she herself had been. Her first draft was 300 pages long. “Mary Lee had to remind me this was for second and third graders.”

Both women credit part of the series’ success to Peter Reynolds, now a picture book star in his own right, then a debut artist hired to illustrate the manuscript.

“Peter once told me as a kid he had been a reluctant reader and would literally count the number of pages until the next picture,” McDonald recalls. “He took my manuscript and just started scribbling all over it. Slime dripping down the page, lots of spot art, two-page spreads. He made it so unintimidating.” The compact trim size made the book “a little fat,” McDonald says, “so kids could feel like they were reading a grown-up book.”

Still, momentum built slowly. It wasn’t until after the release of book two, Judy Moody Gets Famous! (2001), that Candlewick decided what they had was a series. “Even then, we said, ‘Let’s venture another contract or two at first,’ ” Donovan recalls.

In the years that followed, Judy’s fan base grew exponentially, ranging from readers who imagine her as a classmate (“There is always an expert in the audience that knows every factoid and sometimes corrects me,” McDonald says), to women actually named Judy Moody (“Mostly they came to the name through marriage”), to those who, unlike Judy, have grown up and write to say they’re now in college. McDonald has no plans to let that happen to Judy.

“I’ve thought about this a lot, but third grade hits a sweet spot for me,” she says, admitting she likes the company she’s keeping: “After all, Ramona was in third grade for something like 25 years.”