As a young parent, Sandy was a self-described "yes mom."

By the time her two sons were 5 or 6, Sandy, who uses a pseudonym online but has been verified by Insider, would let them do just about anything they asked. But they were responsible for the consequences.

"We had like seven boys in the neighborhood and they'd all come over and make cookies," Sandy, who retired at age 62 in December 2019 and has since built her net worth to over $1 million, told Insider. "They would make a huge mess and it was fine because then I'd say, 'OK, now you have to clean up the mess.'"

She had a similar approach when it came to teaching her kids about money, encouraging them to be self-reliant and exposing them to real-world situations.

One of her sons, who goes by the name Drock online, recently became a millionaire at age 35. He calls Sandy "the single biggest financial influencer" in his life.

Here are five of the most important money lessons Sandy taught her boys from an early age.

Sandy gave each of her kids a $200 monthly allowance starting around age 10 or 11. At first they were thrilled, she said, until they realized they were responsible for nearly all of their expenses from toothpaste to hockey team dues (Sandy and her husband would cover essentials like food and doctor's visits).

"You can choose what you want to do, but then you don't have money leftover to do those other things. So make your choices wisely," Sandy remembered telling her sons. "I let them decide those things. Sometimes they made decisions I didn't think were the greatest, but that's how they learned."

Along the way, Sandy exposed them to some of her own frugal habits, at one point helping them sew their own clothes at home.

In addition to a generous monthly allowance, Sandy gave her sons the the opportunity to earn extra cash by picking up household chores.

"There'd always be lists of them on the refrigerator," she said, with the pay listed next to the task. "If they wanted [to buy] something bad enough, they would find those jobs and do them in order to earn that and pay for it," Sandy said.

They also inherited their parents' entrepreneurial spirit. "Their dad and I had a graphic arts business and we worked a lot, but the kids got to see how hard it is," Sandy said. The boys would print flyers to advertise their own businesses, like raking a neighbor's leaves or pulling weeds in the garden, to keep the income flowing.

For Christmases and birthdays, Sandy and her husband would buy a small amount of stocks for their sons in companies they cared about, like the chocolate-maker Hershey's, and showed them how to track the stock's performance in the newspaper.

"It just helps them to get interested in it, learn about it, and see how it grows or goes down," Sandy said. "You know, it can go down and you can lose money, but they see that when it's still in small pieces so it's not so overwhelming." They also gave the boys the choice of when to buy or sell.

Another common gift in Sandy's house: savings bonds. They bought bonds for the boys in small denominations and explained, in essence, the concept of delayed gratification.

"They kept them and waited for them to mature and cashed them in when they got older," Sandy said, adding that interest rates were much higher 30 years ago than they are now.

"Definitely it was like, 'Wow, we've got to wait all this time for this to make money.' But it showed them that's what happens, it compounds and you earn it over time," she said.

Sandy told Insider that her goal as a parent was to make sure her sons were financially independent by age 18.

"I said, 'When I die, if I'm on the way to the hospital in an ambulance and I still have a dime left to my name, I'm going to have the ambulance pull over and buy half a candy bar. I am spending my money. I'm the one that earned it. I am taking it, I'm not leaving it to you guys. You guys can earn your own money. I took care of you till you were adults,'" Sandy said.

It wasn't entirely true, she added, but she didn't want them to think they could slack off and consider her a cushy backup plan.

"A lot of people think I'm too tough or cold," Sandy said, "but I just think when it comes to that stuff, it is the only way to really make kids realize how they can do it themselves."