[3] In 2008 she won two gold medals and a silver at the Beijing Paralympics whilst studying for a master's degree in mathematics at Royal Holloway, University of London.

[4] Christiansen was born two months prematurely with cerebral palsy and suffered from other health problems including jaundice, blood poisoning, a heart attack and a collapsed lung.

[6] London 2012 also saw her win three gold medals at the home Games, in the grade 1 individual championship, freestyle and team competition on her horse Janeiro 6.

Christiansen contested the team gold medal with teammates Debbie Criddle, Lee Pearson and Sophie Wells.

[11][12] In the team open Christiansen, with teammates Lee Pearson, Anne Dunham and Simon Laurens won her second Paralympic gold medal.

She would have joined the GB team of Paralympic gold medallists Sir Lee Pearson, Natasha Baker and Sophie Wells.

In 2019 she started a petition to improve accessibility on the UK's railway network, due to being left stranded on a train in her wheelchair numerous times whilst commuting into London.

[17] Christiansen takes part in the Superhero Series twice a year on her recumbent trike to promote inclusive recreational sport and staying fit and healthy for people with a disability.

[24] Christiansen was educated at Charters School and Royal Holloway, University of London, where she attained a first class master's degree.

[27] She told The Times that working two days a week helped to "lessen the intensity" of competing at a high level in sport.