[3] Guest represented the United States as a 19-year-old at the 1920 Summer Olympics in Antwerp, Belgium, where she received a pair of medals.

Though Guest won her preliminary heat in a time of 1:18.8 and made a nearly two-second improvement in the final, she was unable to beat Ethelda Bleibtrey’s new world record of 1:13.6.

[5][4][6] In the women's 4×100 metres freestyle relay, she won a gold medal with U.S. teammates Bleibtrey, Frances Schroth and Margaret Woodbridge in a new world-record time of 5:11.6.

[4][7] In the Middle Atlantic AAU Diving Championship in Philadelphia in February 1921, while representing the Meadowbrook Athletic Club, Guest swam a 1:09 in the 100 freestyle, defeating frequent rival Elizabeth Becker.

[10] Guest was inducted into the International Swimming Hall of Fame as an "honor pioneer swimmer" in 1990.