At fifteen, she made the decision to fully commit to speed skating, relocating to Nottingham to undergo full-time training at the National Ice Centre.

At the 2013 European Championships in Malmö, Sweden, Christie won gold in the 1500m[6] and 1000m, and took the overall silver medal behind defending champion Arianna Fontana from Italy.

[11] At the 2013 World Short Track Speed Skating Championships in Debrecen, Hungary, Christie won a bronze medal in 1000m.

At the 2014 World Short Track Speed Skating Championships in Montreal, Quebec, Canada, Christie won a silver medal in 500m and came 4th overall.

She reached the A final of the 500m, but was disqualified when she collided with Italian skater Arianna Fontana, finishing eighth after being ranked below the B finalists.

[21][22] She competed in the 1500m event two days later, where she was disqualified in the heats for not crossing the finishing line, reportedly only 1 cm off the permitted leeway.

[32] On 14 December 2021, Christie announced her retirement from short track speed skating after an ankle injury prevented her from qualifying for the 2022 Winter Olympics in Beijing.

[33] Just over two months after her announcement, during a live TV interview, Christie indicated a potential return to short track speed skating and expressed hopes of competing at the 2026 Winter Olympics in Milan and Cortina d'Ampezzo.

[34] She stated that she would have to self-fund her next Olympic bid and is expecting to train outside of the United Kingdom, with an intention to focus on the shorter 500 and 1000 metre distances.

[36] She was in a relationship with Hungarian short track speed skater Shaolin Sándor Liu from October 2015, before breaking up at the 2018 Winter Olympics.

[37][38] Christie discussed via a social media post in 2019 highlighting mental health awareness that she had suffered from depression and anxiety for a two-year period, including self-harm.