Rebekah Mercer grew up in Westchester County, New York, the second of three girls. She attended Stanford University, where she received a dual BS in Biology and Mathematics and an MS in Operations Research and Engineering Economic Systems. She worked as a trader for a New York financial firm before retiring to raise her four children. She serves on the boards of several nonprofit organizations. With her sisters, she also owns and runs Ruby et Violette, a gourmet ice cream and chocolate chunk cookie company.