as a 15-year-old, she won three gold medals and one silver at the 1964 summer olympics in tokyo, japan. she won the women's 100-meter butterfly, and was a member of the winning u.s. teams in the women's 4×100-meter freestyle relay and the women's 4×100-meter medley relay. she also took second place in the women's 100-meter freestyle, finishing behind australian dawn fraser, for a total of four medals.