Barbara Banke worked her whole life to become a real estate lawyer. Then, she realized that her husband — who'd started a wine company — was much happier than she was.

In 1990, Banke left her successful law career behind to join her husband Jess Jackson's wine business Jackson Family Wines. Today, the 71-year-old has an estimated $2.6 billion net worth, largely from the company, and she's the richest self-made woman newcomer to Forbes' annual billionaires list, as of Tuesday.

Banke became a co-proprietor of the Santa Rosa, California-based wine company after marrying Jackson in 1984, Fortune reported in 2014. She became its chairwoman after Jackson's death in 2011. The company is now reportedly the 10th-largest wine producer in the U.S. It owns 40 wineries around the world, according to its website.

Before Banke joined the wine business, she was a land use and constitutional law attorney who argued multiple cases in front of the U.S. Supreme Court and Courts of Appeals, Jackson Family Wine's website says.

"When I was practicing law, it was 10% fun, and that was arguing in court and writing legal briefs," Banke told NBC News Now in October 2023. "My husband went into the wine business first ... he was having lots and lots of fun, and I was having less. A lot less."

"I've not regretted it for one minute," Banke said of her career change. "It's really not [like] working ... and it's something that is very enjoyable."

Banke started dating Jackson when they were partners at the same law firm, Fortune reported. At the time, he was just starting to turn a single chardonnay grape orchard into a wine business with his two daughters from a previous marriage.

For six years, she helped the company in addition to practicing law and raising their three young children. By the time she left her job in 1990, Jackson was the charismatic face of the company, while Banke came up with strategies to acquire rival vineyards, Fortune reported.

Banke is now the 15th-richest self-made woman in the U.S., according to a Forbes list published in May 2024. Diane Hendricks, chairwoman of construction materials company ABC Supply, holds the No. 1 spot with an estimated $21.9 billion net worth.

When career changes lead to happiness—and financial success

Career changes don't always create billionaires, but they can improve your life under the right circumstances.

If you're feeling stuck at work, changing jobs can sometimes help make you happier and more confident about the direction of your career, according to research from Harvard University and Northwestern University published in the 2024 book "Job Moves: 9 Steps to Making Progress in Your Career."

Specifically, improving your career satisfaction often involves letting go of your "perfect" job, Michael B. Horn, one of the book's authors, told CNBC Make It in December.

Decide what matters to you, and pick a job that helps you prioritize your values, Horn recommended. You might sacrifice a promotion to choose a different job that's closer to family. Or, you might leave the job you enjoy to take a higher-paying 9-to-5 that gives you more financial flexibility to achieve your goals outside of work.

"You're making choices about how to spend your time, who you'll spend it with and the trade-offs you'll make," said Horn. "If those choices don't align with the type of progress you're seeking, that could quickly lead to dissatisfaction and burnout."

Banke gets the most fulfillment from working with her family, she told NBC News Now. She's worked with her son-in-law, who is the company's vice chairman, and her stepdaughters for more than 35 years. All three of her children, their spouses, her step-grandchildren and other family members are also part of the business, according to the company's website.

"[Running this company] was something I really want to do because ... it's a family business," Burke said.

Do you want a new career that's higher-paying, more flexible or fulfilling? Take CNBC's new online course How to Change Careers and Be Happier at Work. Expert instructors will teach you strategies to network successfully, revamp your resume and confidently transition into your dream career. Pre-register today and use coupon code EARLYBIRD for an introductory discount of 30% off $67 (+taxes and fees) through May 13, 2025.

Plus, sign up for CNBC Make It's newsletter to get tips and tricks for success at work, with money and in life.