Emma Sadler turned her life around during the pandemic, going from a laid-off service worker with $15,000 in debt to a gainfully employed UX designer with almost no debt, earning $75,000 a year through two jobs.

The 29-year-old single mom, who shared her journey on CNBC Make It's Millennial Money series earlier this year, has been lucky. One big advantage is that she and her 9-year-old daughter have been able to live with Sadler's mother in the one-bedroom apartment on Manhattan's Upper West Side where Sadler grew up.

The rent-stabilized unit, which Sadler has lived in since she was a baby, has been in her family since her dad moved into it in the 1970s. Because rent stabilization laws only allow landlords to raise rents by a small, set amount each year, Sadler's apartment is much cheaper than comparable homes in the area.

The apartment features a cozy dining nook, as well as a living room and separate kitchen. The walls are decorated all the way up to the high ceilings with Sadler's dad's artwork. The prime location also puts Sadler close to both the American Museum of Natural History and Manhattan's spacious Riverside Park.

The rent costs just $1,400 per month, and Sadler pays $400. (The average rent for a one-bedroom apartment in New York City is around $2,500.)

As a part of the arrangement she has made with her mother, Sadler also picks up the food bill for the entire family, spending between $450 and $500 each month on groceries and $150 to $200 on takeout. Heat and hot water are included with the rent, while Sadler's mother pays the internet and electricity bills.

Sadler also pays about $27 per month for the household's Hulu, Spotify and Disney Plus memberships, and spends $40 every month on her cell phone bill.

Having three generations living in a one-bedroom apartment can sometimes get cramped, but being able to live with her mom during the pandemic has been a life-saver, money-wise, Sadler says. "If I had to pay [more in rent] I would be paycheck to paycheck," she explains.

The arrangement also benefits the family in other ways. Sadler's mother is able to spend more time with her daughter and granddaughter, and Sadler is able to avoid some babysitting costs if she needs to leave the house.

Sadler plans to continue living with her mother for at least another two years while building up her investments and putting money into her high-interest savings account. Her goal is to move out eventually, but hasn't decided yet if she wants to rent or buy.

Sadler's prime location has also helped her stay active with her daughter without breaking the bank. "The great thing about living in New York City is that there are a lot of free things that you can do with your kids, including going to the park and just taking walks from place to place," she says.

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