Throughout her youth, Gascon played exclusively on boys' teams. She initially played as a forward but moved to goal at the suggestion of a coach, who felt she could excel in the position. During 2016 to 2018, she played for the Basses-Laurentides Conquérants in the Quebec bantam AAA league. In 2018, she was invited to training camp for the Phénix du Collège Esther-Blondin in the Ligue de hockey midget AAA du Québec.[1] After posting the best statistics of all goaltenders attending the camp, she was selected to the team and became the first girl to play full-time in the boys' AAA midget league in Québec.[2][3]
In the 2019 draft of the Quebec Junior Hockey League (LHJQ or LHJAAAQ), she was selected 13th overall by the Collège Français de Longueuil, becoming the second female player to be drafted into the LHJQ after Ann-Renée Desbiens was drafted by the Loups de La Tuque in 2012. Her first appearance with the Collège Français came on February 23, 2020, in a game against the Rangers de Montréal-Est, in which she served as the backup netminder to Gabriel Waked. She became the third female player to participate in a LHJQ game and the first in nearly two decades, following in the footsteps of Manon Rhéaume, who played with the Jaguars de Louiseville in the 1991–92 season, and Charline Labonté, who donned a Panthères de St-Jérôme sweater during the 2000–01 season.[4]
On March 19, 2022, Gascon became the third woman to play in the Quebec Major Junior Hockey League (QMJHL) when she started in goal for the Gatineau Olympiques, ultimately losing 5–4 in overtime to the Rimouski Oceanic.[7] On April 1, 2022, Gascon became the second woman to win a match in the QMJHL (after Labonté in 2000), backstopping the Olympiques to a 7–3 victory over the Drummondville Voltigeurs.[8]
In her first season with the Bulldogs, Gascon had seven shutouts, which combined with the six posted by teammate Hailey MacLeod were the most of any team in the NCAA. The final of those shutouts was a 1–0 double-overtime victory against UConn in the NCAA tournament. The starter for 21 of the Bulldogs' 39 games, Gascon ranked fifth in the NCAA with a .946 save percentage.[9]
Gascon played for Canada's National Women's Development Team at the 2024 Six Nations tournament in December 2024, part of the 2024–25 Euro Hockey Tour.[13]
^"Emma Peschel Receives WCHA Honor". LetsPlayHockey.com. Lets Play Hockey. November 6, 2023. Retrieved February 4, 2024. Former Benilde-St. Margaret standout continues solid play