Maria Sharapova first picked up a tennis racket at age four in her hometown of Sochi, Russia. By age six, she showed so much promise that tennis legend Martina Navratilova noticed her and recommended that her family move to the U.S. for more training opportunities. Shortly after, the rising star and her dad flew from Moscow to Miami to develop her game at Nick Bollettieri's prestigious tennis academy. They arrived with just $700 and didn't know a word of English. While Sharapova trained all day, her dad worked multiple low-wage jobs to cover rent, necessities and tennis lessons. They slept on a pull-out couch in a small apartment owned by a middle-aged Russian woman, Sharapova writes in her new book "Unstoppable": "We paid $250 a month for the use of the kitchen and bathroom, as well as the living room, giving us access to the television, which was important. That's how I learned to speak English."

Maria Sharapova won her first Grand Slam at age 17 Jeff Overs | Getty Images

The sacrifice paid off: A decade after moving to the States, at age 17, Sharapova won Wimbledon. That was the first of what would be five Grand Slam titles, and it came with a sizable paycheck: £560,500. Today, the 31-year-old has earned more than $38 million in career prize money, despite a 15-month suspension from the WTA, and was the world's highest-paid female athlete for 11 straight years. Growing up with very little has influenced how she manages her millions today, she tells CNBC Make It. Despite her success on the court, she plans for the future as if her tennis career could end tomorrow. That's part of the reason she launched her candy company, Sugarpova, in 2012, with the long-term goal of building it into a lifestyle brand after leaving tennis. Her candy line, which includes chocolates and gummies, is now available in 22 countries and sold via a variety of retail partners as well as online. "When you're young and you're successful and you're doing well and things are automatic for you in your life, you tend to think that that will continue for years on end," says Sharapova, who overcame a serious shoulder injury in 2008. "It's important to also be realistic about what can happen tomorrow; about injuries; about someone leaving your company; about another company coming in and being a competitor of yours."

Maria Sharapova launched Sugarpova in 2012 Courtesy of Sugarpova