[3] Her first achievement in her international competitions is two gold medals in the big air and slopestyle events at the 2023 Lithuanian National Championships, held in Druskininkai.

[4][5] Then she represented Ukraine at the 2024 Winter Youth Olympics, held in Gangwon, South Korea, finishing 8th in the big air event.

[6] At the 2024 World Junior Championships, held in Livigno, Aniichyn won a bronze medal in the big air event firstly in the history of Ukrainian national team.

[7] Mariia also came first at the 2023-24 FIS Freestyle Skiing European Cup, held in Kotelnica Bialczanska, in the big air event.

[8] On 19 January 2025, Mariia won a silver medal in big air at the Winter Universiade in Turin.