On a hectic Saturday before Christmas, writer Kate DiCamillo stands in front of a buzzing crowd of toddlers and children at the Red Balloon Bookshop in St. Paul. She is dressed in her usual black top and bluejeans, and her white-blond hair curls around her watchful face. Some of the kids sit cross-legged on the floor; some perch demurely on chairs or on a parent’s lap; some peer around the edges of bookshelves; some bat absently at furry puppets that hang from a display.

DiCamillo is used to the pandemonium that is a crowd of children. She is not rattled. She keeps things moving.

She reads a few pages from her new book, “Leroy Ninker Saddles Up,” and just as she is asking if anyone has any questions, one small rogue child suddenly shoots out of the pack, crawling fast, like Bart Simpson’s baby sister, circumnavigating the tiny island of space where DiCamillo stands, and then crawling off again. She watches him go and says, “I might have a question,” and everybody laughs.

A boy raises his hand. “Why do books have words in them?” he asks.

DiCamillo looks thoughtful. “That’s what you call an existential question, but I’m up for it,” she says.

“Words are a special way for me to tell you a story and I don’t have to be there. It’s like magic.”

As far as DiCamillo is concerned, everything about books is magic, especially the fact that she is one of the people who makes a living by writing them.

All 18 of her books, beginning with “Because of Winn-Dixie” in 2000, have been bestsellers or much lauded or deeply loved or all of those things. (Mostly, all of those things.) DiCamillo, this year’s Star Tribune Artist of the Year, won her second Newbery Medal in January for “Flora & Ulysses” — something only five other authors have done in the award’s 93 years. She was also named National Ambassador for Young People’s Literature by the Library of Congress, a two-year appointment that takes her all over the country, speaking to children, educators and librarians about her favorite topic, reading.

“Kate was on everyone’s shortlist,” said Luann Toth, managing editor of School Library Journal and a member of the ambassador committee. “Her books are a perfect blend of literary merit, accessibility and heart. It’s a good thing she’s so young and dynamic. She’s got rock-star status now.”

DiCamillo grew up in Clermont, Fla., moving there from Philadelphia at age 5 with her mother and older brother in hopes that warmer weather would improve her frail health. (She was hospitalized with pneumonia many times as a toddler.) Her father was supposed to join them, but he never did; she’s not sure why, and they are still estranged. Family life in Florida was just the three of them: mother, brother and Kate — and their dog, always a dog.

She graduated from the University of Florida with a degree in English and then sort of frittered away the next few years, working at the Circus World theme park and at a campground, thinking about writing, wanting to write, determined to be a writer, but not actually writing.

In 1994, when she was 30, she tagged along with a friend to Minneapolis, a place she had never been. It was something of a risk. She didn’t have a job. She didn’t have a winter coat. (“I thought, how cold could it be? When it gets cold in Florida, you just run.”) But it turned out to be the best thing she could have done.

“I could go 15 minutes in any direction and be at a bookstore or a library,” she said. She got a job at the Bookmen, a book warehouse and distribution center in Minneapolis. Her goal was not to become a full-time writer; she didn’t dare dream that big. She just hoped eventually to cut her hours at the Bookmen to 30 per week and make up the rest of her income through writing. And so she began to write, diligently, every day, two pages.

And for a long time, she didn’t sell a thing.

• • •

At Red Balloon, a girl asks, “Which book is your favorite?”

“Of my books?” DiCamillo asks. “Which of my books is my favorite?” The child nods. DiCamillo doesn’t answer the question right away. Instead, she asks if the girl has any siblings. Yes. She asks if the girl has brought a parent with her. Yes. So DiCamillo addresses the parent: “Which of your children is your favorite? Which one do you love the best?” And there is a little gasp.

“That’s how I feel about my books,” DiCamillo says. “I love them equally but differently. I think of them all as deeply flawed but lovable, which is not what I’m saying about you.”

• • •

No, she doesn’t have a favorite, but she does has a special fondness for “Because of Winn-Dixie,” the book that started it all.

“Nothing would have happened without ‘Because of Winn-Dixie,’ ” she said. “I wouldn’t have my house. I wouldn’t have anything. I got where I am, wherever that is, because of that book.”

It took a long time. Years. At first, she wrote short stories. Two pages a day, every day. She sent them to literary journals, and the literary journals sent them back. She kept writing. Years passed.

And then the Bookmen assigned her to the third floor. Children’s books. Oh, my. She began to read.

“ ‘The Watsons Go to Birmingham,’ by Christopher Paul Curtis, was the first children’s novel I read as an adult,” she said. “It talks about hugely important things, but it’s incredibly funny. I didn’t know you could do that with a children’s book. A book like that, or like ‘Charlotte’s Web,’ it tells you the truth and makes the truth bearable.”

She began to write a children’s book. “I think I found exactly where I’m supposed to be,” she said. “If I had not been assigned to the third floor, I don’t know that I would have discovered it.”

One day writer Louise Erdrich came into the Bookmen, and some of DiCamillo’s friends kind of pushed her forward, urging her to introduce herself. She remembers the moment vividly: Erdrich, she said, stopped and looked at her. “How long have you been writing?” Erdrich asked. “Four years,” DiCamillo said.

“See if you can hang on for a couple more years,” Erdrich said. “Things opened up for me in the sixth year.”

“That was so decent of her,” DiCamillo said. “To look at me, right in the eye, and really see me. That meant so much.”

Erdrich remembers it, too. “I walked away thinking, ‘warm and fearless.’ Which is very good in a writer.”

• • •

The crowded bookstore is growing warm, and some of the smallest children are starting to rock and hum. Someone has asked DiCamillo about the Mercy Watson books, her series about a pig who loves buttered toast, and DiCamillo is explaining how those books came to be.

“Can everybody hear me?” she asks. “Because this is fascinating.” And the humming drops and the children stop fidgeting and they listen. DiCamillo knows how to work a crowd of kids.

• • •

In “Flora & Ulysses,” Flora, the 10-year-old heroine, says, “This malfeasance must be stopped.” She asks her father to “quit speaking euphemistically.” She urges the squirrel, Ulysses, to “obfuscate.” Other characters “posit.” The squirrel has an “arch-nemesis.”

Writing books for children, said Andrea Tompa, DiCamillo’s editor at Candlewick Press, is harder than people might think. “There is a perception that kid books are easier — easier to write, easier to read, not as sophisticated as adult books. I think that’s false,” Tompa said. “Those words have to be well-chosen. There’s no room to hide. It’s like writing a poem.”

DiCamillo never wonders if a word is too hard for kids. Instead, she wonders, “Is this the right word? How does it sound when you read it aloud?” And if the word sends a person to a dictionary, well, that’s part of the joy of reading.

She began writing “Winn-Dixie” in the late 1990s, during a frigid Minnesota winter when she was missing Florida, her mother and her dog, Lucy, whom she had left behind.

“The high was 37 below for three days in a row,” she said, hardly exaggerating at all. “I had this Florida car, and I’d open the car door and little pieces would fall off. They’d frozen to death.” Writing allowed her to immerse herself in the remembered warmth of home.

She joined a writing group run by Jane Resh Thomas, the author of 14 books for children and a longtime teacher in MFA programs, including at Hamline University in St. Paul.

“I was just shocked by the quality of her writing,” Thomas said. “I told her at the front door as she left, ‘You’re going to be famous, you know.’ And she said she had had so many rejections that she couldn’t believe in herself anymore.

“I told her that I would believe in her for her.”

“Winn-Dixie” was published in 2000, six years after DiCamillo’s move north. It was named a Newbery Honor Book — a runner-up to children’s literature’s top prize — and won the Josette Frank Award and the Mark Twain Award and was made into a movie.

“I told her she was going to be famous,” Thomas said, “but I didn’t think she was going to be famous overnight.”

• • •

The questions end, and DiCamillo signs books and poses for pictures. She is not much bigger than the kids she poses with, slender and tiny, almost elfin, but with a great booming happy laugh, a HA HA HA that everyone recognizes. Later, when she is up in the loft of the Red Balloon, signing books, she belts out a HA HA HA and people below look up and call, “Kate!? Is that you? Kate!” And Kate peers over the edge of the loft and invites them up. Is that your dog? she says. Bring your dog up! And they do.

• • •

Every morning, DiCamillo’s coffee maker clicks on at 5:30 a.m., and she comes downstairs, pours herself a cup of black coffee and carries it into her neat-as-a-pin office. She sits at a plain wooden kneehole desk that faces a blank wall, and she writes. Two pages. Every morning. No distractions. No excuses.

Her discipline is legendary; her friends give her all kinds of grief about it.

“She’s one of the most hardworking people I know,” her editor, Tompa, said. “She could coast on raw talent if she needed to. But that’s not the way she is.”

When DiCamillo starts a book, “The primary thing in my head is I’ve got something by the tail and I don’t want to let it go,” she said. But as the book progresses, the feeling shifts. “Later, it’s more a feeling that I’m carrying it in my arms and I don’t want to let it drop.”

Now 50, she has never married and has no children, but she has a ton of friends and a dog named Henry. “I believe that you can have anything you want, but you can’t have everything you want,” she said. “I have access to friends’ kids. I don’t know what kind of a parent I’d be, but I’m the aunt of your dreams.”

She doesn’t really take vacations, doesn’t waste time surfing the Web. Her publicist handles her Facebook presence. (DiCamillo writes the posts.) She sees no point in noting the thumbs-ups or the praise fans might write. “It never fills you up,” she said. “If you go looking for approval, you’re never going to be satisfied.”

She’s found her path in life, and she is devoted to it. “I’m a solitary person given to intimate socializing,” she said. “I’ve got a lot of wonderful friends who take good care of me. But I’m happier if I’m working. I’m happier if I have a story.”

• • •

Someone at the Red Balloon asks the inevitable question, the one that DiCamillo will never answer. “What’s my next book? A novel,” she said. “It will come out in spring 2016. What’s it about? I can’t say. What’s the title? I won’t tell you. Is it any good? I don’t know.”

Her editor is happy to answer that one a few days later. “It’s spectacular,” she said emphatically.