Clark was born and raised in Dallas, Texas, the daughter of Lorraine and Banks Clark. She studied the piano and attended the Hockaday School, an all-girls school in Dallas. She attended the Interlochen Arts Academy before going to Yale University, graduating in 1982. At Yale, at the age of eighteen, she sang the role of Mabel in Gilbert and Sullivan's comic opera "The Pirates of Penzance". She also sang the title role in Gilbert and Sullivan's "Patience", and directed a production of "Ruddigore" for the Yale Gilbert & Sullivan Society. After college, Clark studied at New York University's Musical Theatre Master's Programas a stage director and began to direct operas and musicals professionally. Although she continues to direct, she has primarily focused on singing and acting.