[5] FitzGerald set a new under-17 record for 3,000 metres, and in December 2022 finished fourth in the under-20s European Cross Country Championships in Turin, competing as a seventeen year-old.

[7] In January 2023, FitzGerald turned down the opportunity to compete at the 2023 World Athletics Cross Country Championships in Bathurst, Australia because of concerns she holds about contributing to climate change.

[8] In a letter to UK Athletics she wrote that “The reality of the travel fills me with deep concern”, adding that "I was just nine when the COP21 Paris Climate agreement was signed.

[13] In October 2023, Fitzgerald was announced as the winner of the BBC Green Sports Awards 'Young Athlete of the Year' for her refusal to fly to the World Cross Country Championships taking place in Australia.

However, after the race she said she would not take her automatic place at the 2024 World Athletics Cross Country Championships that month, due to travel time and the impact it would have on her A-Levels study.

[22][23] She was selected for the 2024 World Athletics U20 Championships in Lima, Peru, where she placed fourth in the final of the 3000 metres in a personal best time of 8:57.01.

[31] She broke the European under-20 3000m indoors record in February 2025, running 8:40.05 in Ostrava to beat Sofia Thøgersen's previous best mark by 10 seconds.