St-Georges made three appearances at the
Canadian Junior Curling Championships in
2016,
2018 and
2019. In 2016, Team Quebec, skipped by her sister Laurie, finished the tournament with a 6–4 record, finishing in sixth place. In 2018, her team made it all the way to the final before losing to Nova Scotia's
Kaitlyn Jones, earning the silver medal. In 2019, her team lost to British Columbia's
Sarah Daniels in a tiebreaker to qualify for the playoff round. Cynthia skipped her own team at the
2019 Canadian U18 Curling Championships that season as well. Her team finished 3–3 after the round robin, just missing the playoffs. Also during the
2018–19 season, Team St-Georges lost in the final of the
Curl Mesabi Classic World Curling Tour event. Team St-Georges started competing more frequently on the tour the following season. They competed in their first
Grand Slam of Curling event at the
2019 Tour Challenge Tier 2 where they lost in a tiebreaker to
Megan Balsdon. Team St-Georges also competed in their first provincial women's championship at the
2020 Quebec Scotties Tournament of Hearts. After finishing the round robin in first place, they lost in the final to
Noémie Verreault 3–1. Due to the
COVID-19 pandemic in Quebec, the 2021
Quebec Scotties Tournament of Hearts was cancelled. Since the defending champions, Team Noémie Verreault, had disbanded, Team St-Georges (the 2020 provincial runner-up) was invited to represent Quebec at the
2021 Scotties Tournament of Hearts, which they accepted. The event was played in a bio-secure bubble in
Calgary,
Alberta to prevent the spread of the virus. At the Hearts, St-Georges and her teammates received a lot of media attention and fans thanks to their positive attitudes and strong play on the ice. They also defeated multiple higher ranked teams in the tournament including the Wild Card team of
Tracy Fleury (skipped by
Chelsea Carey),
Corryn Brown's British Columbia rink and
Suzanne Birt's team out of Prince Edward Island. Ultimately, they finished the event with a 6–6 record and a seventh place finish. Team St-Georges began the
2021–22 season with a semifinal finish at the
2021 Oakville Fall Classic where they lost to the event winners Team
Jamie Sinclair. They only made the playoffs at one other tour event at the
Stu Sells 1824 Halifax Classic, losing in the quarterfinals to Team
Jill Brothers. Due to the
COVID-19 pandemic in Canada, the qualification process for the
2021 Canadian Olympic Curling Trials had to be modified to qualify enough teams for the championship. In these modifications,
Curling Canada created the
2021 Canadian Curling Pre-Trials Direct-Entry Event, an event where eight teams would compete to try to earn one of two spots into the
2021 Canadian Olympic Curling Pre-Trials. Team St-Georges qualified for the Pre-Trials Direct-Entry Event as the second seed. The team won their opening match, but then lost three straight games and were eliminated from the event. The
Quebec Scotties Tournament of Hearts was again cancelled due to the pandemic and Team St-Georges were once again selected to represent Quebec at the national women's championship. The team could not replicate their successful run from 2021, finishing the
2022 Scotties Tournament of Hearts with a 3–5 record. They won their opening two matches against Alberta's
Laura Walker and the Yukon's
Hailey Birnie and their last game against Nova Scotia's
Christina Black. Aside from playing for her sisters team, Cynthia skipped the Quebec junior women's team at the
2021 World Junior Qualification Event, only winning one of her five round robin games. ==Personal life==