When Adina Rishe Gewirtz was 12, she had what she calls a “life-changing” experience: she read Harper Lee’s To Kill a Mockingbird. “I was so taken with the voice and how she just wrapped me up in that experience,” Gewirtz said. “I finished the last page and thought, ‘I want to do this.’ ” And although she knows that the 12-year-old her would have been “horrified” if she’d had any idea that achieving that goal would take 30 years, Gewirtz says that she “needed a lot of living to become the writer I wanted to be.”

Plus there was the little matter of earning a living: both of her parents were natural storytellers, she says, but while her father fed her dreams of writing fiction, her mother wanted to make sure she could pay her rent. So Gewirtz majored in journalism and worked as a freelancer, mostly on business stories, covering everything from real estate to car tires. Along the way, she and her husband—they live in Silver Spring, Md.—raised five kids. The oldest, a set of twins, are now 23; the youngest is 15.

She also wrote fiction, and had come up with the character and voice of Annie B., the 11-year-old narrator of Zebra Forest (Candlewick, Apr.), when she was in college. Between then and finally sitting down to write when her youngest child started first grade, she kept notes. But, she says, she “never told people I wanted to be a novelist. The practical voice in my head thought, ‘Probably a million people want to be novelists.’ ”

When Zebra Forest, a middle-grade book that tells the story of Annie B., her brother, and a prison escapee, was finished, she contacted all of the agents she could find who accept e-mail queries, and Ashley Grayson (who runs an eponymous agency in California) asked to see more. Gewirtz was at a parent-teacher night at her daughter’s school when she got Grayson’s call saying he wanted to represent her.

Grayson spent a year shopping the manuscript, and although Gewirtz says she despaired at times, he never lost faith. “Don’t worry,” she says he told her. “Write another book. You should be writing a book a year.” So she did, picking up another story she’d been thinking about for years. Then, she says, she started looking to see who’d published the stories she loved, and noticed that the Kate DiCamillo books she and her kids liked best had been published by Candlewick. Gewirtz credits DiCamillo with giving her a broader idea of what was possible in books for young readers. She mentioned Candlewick to Grayson, and he contacted president and publisher Karen Lotz, who ultimately bought both books. That second book, Blue Window, is due out in fall 2014; it’s a fantasy, set in an invented world. Gewirtz connects both books back to her parents: Zebra Forest is realistic like her mother, while the second book reflects her father’s influence. She’s currently at work on a sequel to Blue Window.

Asked about the experience of working with Grayson and Lotz, Gewirtz brings up another childhood memory. Her father, she says, would get little gifts and hide them, then bring them out unexpectedly, so any day might contain a wonderful surprise. Working with her agent and editor was like getting “these constant little surprises from my father’s closet.” And the final surprise is being able to write full-time, the fulfillment of a lifelong dream, Gewirtz says, “to be able to just sit down in the morning and think about story.”