A student athlete, she began throwing while in junior high school, but also participated in other events, and made the Nova Scotian heptathlon team in 2013.

[3] Continuing to distinguish herself during her studies at Windsor, Mitton won the U Sports title and was named USports female field athlete of the year in 2018.

The latter was the first time she had competed in a shot put event with qualification and finals on the same day, something she simulated extensively in advance, which she later said gave her a considerable advantage over her competitors.

[7] After graduating with a Bachelor of Science degree, Mitton delayed plans to pursue further studies in marine biology to continue her athletics career, relocating to Toronto and for a time residing with fellow Canadian shot putter Brittany Crew.

[2][8] Following her Universiade victory, she made two other major international appearances in 2019, finishing sixth at the 2019 Pan American Games in Lima, and then making her World Championship debut at the 2019 edition in Doha.

Mitton obtained the necessary Olympic qualification mark at an event in Auckland, also setting a new personal best of 18.84 m, but said that the most gratifying element was competing against and beating legendary New Zealand shot putter Dame Valerie Adams.

[4][8] Returning to Canada in early March, she had intended only a short visit to Nova Scotia before turning to Toronto, but the onset of the COVID-19 pandemic meant she remained at home for several months.

[4] The pandemic significantly affected the international athletic calendar in 2020, including the delay by a full year of the 2020 Summer Olympics, but Mitton continued training and credited Crew as a valuable partner and rival in local events.

In May, she broke Crew's Canadian outdoor record with a throw of 19.58 m.[11] This in turn earned Mitton her first ever Diamond League invitation, to attend the 2022 Bislett Games in Oslo, a longstanding goal.

[23] [24] By the end of the indoor season, she had developed bone chips in her right elbow, which she contemplated surgical options for, but did not want to pursue in advance of the upcoming Summer Olympics.

[6] Beginning the year's outdoor major competitions on the 2023 Diamond League circuit, she finished fifth in her initial outing at the Meeting International Mohammed VI d'Athlétisme de Rabat with a best throw of only 18.56 metres.

[30] Beginning the Olympic season, Mitton was named co-captain of the Canadian delegation to the 2024 World Athletics Indoor Championships alongside Alysha Newman.

[34] As the defending World champion unexpectedly failed to qualify, Mitton was perceived as the gold medal favourite going into the final, but struggled and finished twelfth of the twelve competitors.

[35] Following the disappointment at the Olympics, Mitton resumed competing on the 2024 Diamond League circuit, earning medals that she would describe as "critical to my mental well-being.