[9] She was the Australian team’s flag bearer at the 2017 Maccabiah Games in Israel, where she won a silver medal in the 10 km race walk.

[12] Montag earned selection for Australia at the 2018 Commonwealth Games through a silver medal performance behind Beki Smith at the 2018 Australia and Oceania Race Walking Championships, setting a personal best of 1:31:26 hours in her second ever competitive outing over the 20 km distance.

[13] Montag was the gold medalist of the 20 kilometres race walk at the 2018 Commonwealth Games, at 20 years of age.

[14][15] She came in sixth in the final of the Women's 20 km walk in the Tokyo 2020 Olympics in a time of 1:30.39, at 23 years of age.

[16] Montag won the gold medal at the 2022 Commonwealth Games, repeating in the 20 kilometers race walk.

[18] At the 2023 World Athletics Championships in Budapest, Montag won the silver medal in the women's 20 km walk, 25 seconds behind the winner.