[3] Zahnd played for two swimming clubs in Geneva, before she trained under head coach Dirk Reinecke as part of the Swiss national team.

[7][8][9] On the first day of the Games, Zahnd teamed up with Dominique Diezi, Marjorie Sagne, and 16-year-old Seraina Prünte in the 4×100 m freestyle relay.

Swimming the anchor leg, Zahnd recorded a split of 56.50, the fastest in Swiss history, and her team finished the race in seventh place and fifteenth overall in a final time of 3:48.61.

[10][11] Four days later, in the 4×200 m freestyle relay, Zahnd placed twelfth, along with Chantal Strasser, Hanna Miluska, and Flavia Rigamonti, in 8:10.41.

[12][13] In her final event, 4×100 m medley relay, Zahnd swam the anchor freestyle leg, with Diezi (backstroke), Carmela Schlegel (breaststroke), and Carla Stampfli (butterfly), to pull off another fifteenth-place effort for the Swiss team in a time of 4:15.54.