Sarah Knauer first became an entrepreneur in high school—as a piano teacher. “I went from house to house and put in long hours,” she says. Knauer could make $60 to $70 an hour at the time, and it became a perfect job through her college years. Getting her real estate license as a college junior dovetailed with her desire to continue working with families and children, and led to her next steps professionally. The first buyer she ever represented bought a $10 million house. Today, Knauer, 27, offers her clients concierge-style services, including hiring painters and stagers, getting trees trimmed, and scheduling inspections. Knauer’s mentor and current team leader, Anthony Marguleas, took her under his wing when she was 22. “He gave me responsibilities beyond my years and pushed me to take risks that have paid off in my career and in my life,” she says.