You can take the woman out of work, but you can't take the work out of the woman.

At least, that's the case for J.P. Livingston, who retired at 28 with a nest egg of more than $2 million, which she saved while living in New York City.

With a job in finance that paid $100,000 by the end of the first year, Livingston was able to tuck away 70% of her take-home pay. From there, she invested 40% of that and saved 60%. When she received yearly raises, instead of increasing her spending limit, she saved the difference for retirement.

But to her surprise, her corporate years weren't the last time she would see a flow of income.

"When I was contemplating early retirement while working, I was very burnt out," Livingston previously told Business Insider. "I imagined I would want to sit on the couch and eat bonbons, sleep in late, that kind of thing. I did do that, but it gets boring eventually, and I ended up getting active again with different hobbies and projects. Eventually, one or more of those projects yielded income. It's hard to be awake for 60-plus hours a week and not find a single enjoyable way to earn some money."

She began writing a personal-finance blog, The Money Habit, because the topic had been of interest to her for years, she said.

"I didn't expect it to make any money at all because there are a million blogs out there, but it eventually got big enough that between the hosting and email bills, I decided I should figure out how to monetize it enough to pay its own bills," she told Business Insider. After its first year, she said "it made over $62,000 with me spending less than five hours a week writing about things I wanted to write about."

Setting up passive income through blogging

Livingston started writing on the blog in August 2016, covering everything from investing and saving to planning for early retirement, she said. In 2017, after she had attracted a few readers, she researched how others monetized their blogs.

It turns out that affiliate commissions, in which she refers a product or business on the blog and receives a percentage of a sale or a flat commission from that company if a reader makes a purchase, were a huge opportunity. She earned $60,162 in 2017 with this strategy.

Much of the money was passive income, meaning she didn't have to put in endless hours to see her work pay off. The lasting value is a bonus of the side hustle, Livingston said.

"If you build your own blog or side business, you have created an operation that can continue to throw off cash for you in the future," she said.

Near the end of 2017, Livingston began adding advertisements to the site, something that earns her $1,000 to $2,000 a month. Because she started using ads so late in the year, they brought in only an extra $2,164 in 2017.

Livingston said her blog earned $14,000 over three months while she was caring for her new baby. Shutterstock

"Earlier this year, I had a kid. I was completely offline for three months, but the blog generated over $14,000 in that time," she said. Livingston had posts scheduled to publish once a week during this time, few of which had affiliate links, so most of the revenue came from previous posts and ads.

She added that "it has been amazing getting to talk to thousands of other people who are passionate about the same things as I am."

In fact, if she had known it was still possible to generate income while retired, Livingston thinks she would have retired even earlier than she did.

"I wanted to be absolutely sure I didn't have to work at all once I pulled the trigger," Livingston said. "If I knew then what I know now, I would at least modify my target retirement number to need less buffer because I knew I could work part time as a fallback to supplement our needs."

She added: "But the reality is that if you have the initiative and discipline to retire early, you are probably the kind of person who likes to get very engaged in new projects and hobbies, which will eventually yield an income."