LaVine won her first medal in international competition, a gold, at the 1951 Pan American Games in Buenos Aires, Argentina.

[1][2] She was a member of the winning U.S. team in the women's 4×100-meter freestyle relay which included teammates Carolyn Green, Betty Mullen and Sharon Geary.

[1][2] Individually, she also won a silver medal for her second-place finish in the women's 100-meter freestyle.

[1][2] One year later, LaVine represented the United States at the 1952 Summer Olympics in Helsinki, Finland.

[1] She received a bronze medal as a member of the third-place U.S. team in women's 4×100-meter freestyle relay, together with American teammates Marilee Stepan, Jody Alderson and Evelyn Kawamoto.