Rachel Adams has the kind of success story most real estate professionals strive to emulate. Adams, a sales associate with Keller Williams Realty in Roseville, Calif., went from closing 39 transactions in 2012—her first year as an agent, at age 26—to 123 just two years later, landing in The Wall Street Journal's top 1 percent of salespeople nationwide. The rapid rise in her business made her life appear perfect.