Elon Musk is one of the world’s richest people, but he didn’t grow up wealthy, according to his mother Maye: She says she had to scrimp, save and hustle to raise him and his siblings after her divorce. “Anyone who knows me says they don’t envy my life. I’ve just been through very hard times,” Maye tells CBS News in a recent interview. “I had to pay the rent, I needed a roof over our head and food for us to eat.”

At 70, Maye is a model, nutritionist and full-time fan of her three grown entrepreneurial kids, Elon, Kimbal and Tosca but, for many years, modeling was a way to make money and maintain her family. She says she did it “to survive.” And at one point, she had to work a total of five jobs: “I was a research officer at the University of Toronto. I was teaching two nights a week at a nutrition college and two nights a week at a modeling agency. I modeled and I gave talks, and I had a private practice,” Maye tells Forbes.

When Maye was 22, she married Errol Musk, an engineer, and she became pregnant with Elon while they were on their honeymoon. After that, two other 𝘤𝘩𝘪𝘭𝘥ren followed, but the couple then divorced, leaving Maye, then 31, to raise the 𝘤𝘩𝘪𝘭𝘥ren as a single mother.

Elon says he’s “naturally good at engineering” because of his father, who came from a wealthy background, but his memories of Errol are far from fond: “He was such a terrible human being,” he tells Rolling Stone.

Without him, though, the family struggled to make ends meet. “After my divorce, I had to house and feed three kids without maintenance. Poverty makes you work really hard,” Maye tells the Huffington Post.

Though she had some help from her twin sister Kaye, Maye still recalls the small, daily difficulties. “I remember crying when one of my kids spilled milk. The saying goes, ‘Don’t cry over spilled milk.’ I cried because I couldn’t buy another milk that day,” she says. “I was juggling my private nutrition practice, wellness talks, modeling and kids schooling and activities. Those were busy times. Fortunately, we were healthy and my kids were well-behaved and helpful.”

Once Elon was 17, he moved from his native South Africa to Canada to begin college in North America. Elon lived with one of his mother’s cousins on a farm in Saskatchewan, Canada, until his mom moved to Toronto at age 41 with Tosca. “Fortunately I found a rent-controlled apartment,” she says. “Elon, Tosca and I spent three weeks making it habitable.”

Still, while in Toronto, they lived on a very limited food budget. “We could not afford to dine out. I had a client with a butcher. Once a month he would give me a beef roast. I would cut it up in four pieces, freeze three and cook one so we could have meat once a week,” Maye tells the Huffington Post.

Maye says she hopes Elon learned from her how to use money wisely, and he does seem to have internalized some of her lessons: For a while, he spent only a dollar a day on food, mostly by buying it in bulk. “My threshold for existing is pretty low, I figured could be in some dingy apartment with my computer and be okay,” Musk told Neil DeGrasse Tyson on his StarTalk radio show in 2015.

tweet (Maye family)

In the end, thanks to Maye’s diligence, her family didn’t just manage: Her 𝘤𝘩𝘪𝘭𝘥ren thrived. While Elon now launches rockets and digs urban tunnel systems, Kimbal is pioneering a sustainable food movement and Tosca is making moves via her streaming platform PassionFlix, the Netflix for romance movies.

“People asked, why was I motivated? I would say, I wanted to survive,” Maye says. But now she can be more relaxed about her career, and when she sits for photo shoots, she’s doing it because she’s following her passion. Last year, she made history as the oldest model to star in a CoverGirl campaign.