Thomas began synchronized swimming at age ten, at thirteen she moved to Montreal to further her training. She joined the national team in 2007 and competed in her first world championships that year. Thomas was a two time Olympian competing in the women's team event at the 2012 Olympic Games, finishing fourth, and in the duet event at the 2016 Olympics, finishing seventh. Thomas won two golds at the 2015 Pan American Games, one in the team event and one with her partner Jacqueline Simoneau in the duet. In May 2017 Thomas retired from synchronized swimming, after being on the Canadian national team for ten years.