A member of Sevenoaks Athletics Club, Nicholson finished fifth at the British Schools Cross Country Championships in March 2023. She ran 9:30.05 for the
3000m in the U17s category at the South of England Senior and U20 Championships in June 2023. She won the silver medal at the England Athletics U20 Women's 3000m at
Chelmsford in June 2023, aged 16 years-old. Her time was a personal best of 9:24.17. Nicholson won gold on her schools international debut, in
Grangemouth, Scotland, at the SIAB Home International meet, winning the intermediate girls’ 3000m race by around 20 seconds in 9:25.85. In August 2023, she won bronze in the women's 3000m event in a time of 9:26.00 at the
Commonwealth Youth Games in
Trinidad and Tobago. She made her debut for Team England cross country as part of the victorious England women's junior team alongside
Innes Fitzgerald,
Isobelle Jones, and
Jess Bailey at the London International country event at Parliament Hill, placing second in the individual race in January 2024. That year, she was runner up to FitzGerald at the English Schools Cross Country Championship. In March 2024, she finished as runner up to FitzGerald at the UK Inter-Counties Cross Country Championships at
Wollaton Park to earn an automatic place on the British U20 team for the
2024 World Athletics Cross Country Championships in Serbia alongside
Natasha Phillips and Innes FitzGerald. She finished in 25th place, as Britain finished fifth in the team U20 event. In 2025, she was selected to represent England U20 at the 2025 Home Countries International and the Hannut CrossCup. She was runner-up to Isabelle Jones at the Belgium Cross Cup in the junior women's race, a World Athletics World Tour Gold Event. She won the junior women's race at the 2025 Home Countries International. In December 2025, Nicholson competed in the team under-20 event at the
2025 European Cross Country Championships in Lagos, Portugal. She was subsequently named in the British team for the
2026 World Athletics Cross Country Championships in
Tallahassee, Florida, where she was the leading British finisher in the U20 women's race, leading the British team to a joint-tenth place finish. == References ==