Hayley DiMarco understands worrying about “having it all.” She has authored 30 books, launched her own company, and writes as many as 4,000 words daily.

“That notion of having it all can be exhausting and trying,” DiMarco says. “I have a heart for women who love God, who want to live by his spirit and not by their own. It can be challenging when you’re independent and strong-willed.”

The idea for her latest book, The Fruitful Wife (Crossway, Sept.), came to her as a matter of practicality. With her husband, Michael, she has written books mainly for young adults, like The Brave: Conquering the Fears That Hold You Back (Revell, July). The teen readers they have written for since the early 2000s are starting to grow up and get married, she says.

Hayley DiMarco is used to being in tune with her audience. She was hired by Thomas Nelson in 1999 and moved to Nashville from Oregon, where she worked for Nike. At Thomas Nelson, she says she saw some cheesy materials for young adults that were both proposed and published, so she started writing books of her own.

While her books sold well, DiMarco says she didn’t receive royalties because she wrote them as a Thomas Nelson employee. Then she founded the book company Hungry Planet, which her husband runs as CEO. Creating Hungry Planet helped her find her niche and cultivate what she calls her personal gifting: writing about relationships in an honest and confessional way.

Her focus then was un-churched kids. “I think everyone wants to know what God wants for him or her, and kids struggle with how hot is too hot [sexually],” she says. “They wanted boundaries. Christian authors in the teen relationship world were afraid to be honest. I would write things like ‘If what you’re showing ain’t on the menu, keep it covered up.’”

The Fruitful Wife provides more of that straightforward and no-nonsense advice for a more mature audience. At the core of her message is that women should develop joy, peace, and patience in marriage. “I wanted to write about how to develop the fruit of the spirit when you’re no longer this independent woman,” she says. Women are like trees that grow fruit, she adds. “When we develop the fruit of the spirit, it benefits those around us. A tree doesn’t grow to feed itself, but to feed the people around it.”