 As a teenager, she grew up in Santa Clara, California and trained with the Santa Clara Swim Club in Santa Clara under the coach George Haines, who was noted for leading U.S. Olympic swimmers during the 1960s and 1970s.As a 15-year-old, Rothhammer represented the United States at the 1972 Summer Olympics in Munich, Germany.She won the gold medal in the women's 800-meter freestyle and set a new world record in the event twice, on successive days.