Eleven years ago Michael Kaplan, 42, and his brother Nicholas, 44, started Fashion to Figure, a New York City-based clothing retailer that caters to plus-sized women and teens, a market estimated at $18 billion in the U.S. With 400 employees, a website it launched in 2011, and 26 brick-and-mortar stores between Atlanta and Boston, its revenues approached $50 million last year.