Bush was born at NewYork–Presbyterian Queens in Flushing, Queens on New York. Her parents were Pauline Robinson (1896-1949) and her husband, Marvin Pierce (1893-1969). Her mother died in a car accident. Her ancestor Thomas Pierce, an early New England colonist, was also an ancestor of Franklin Pierce, the 14th President of the United States. She is a fourth cousin, four times removed of Franklin Pierce.