Hernandez began her sporting career as a BMX racer in international competition[1][3] before discovering snowboarding. On 21 October 2002 she experienced an attack of
multiple sclerosis that paralysed her legs for two months.[3][4][5] As a result, she stopped sport and took refuge in writing, publishing two books for Éditions du Rocher and working for
Europe 1 (from 2011) and Le Figaro from 2012, covering the
2012 Summer Paralympics in London.
In May 2012, Hernandez arranged an endurance race for both disabled and able-bodied athletes, travelling from
Lyon to
Bordeaux by
bicycle and
kayak.[3] Then, in 2013, when she happened to try snowboarding again in the
French Alps, she was spotted by a member of the French para-snowboarding team.[3] She was selected for the Paralympic snowboarding team for the Sochi Games in February 2014, with just over a month to prepare, but was encouraged by her performance at the World Para Snowboard World Cup the previous month.[3] She won a silver Paralympic medal at Sochi, with a
snowboard cross time of 2:07.31,[1] and was named a
knight of the National Order of Merit by then-president
François Hollande in June 2014.[1]
In the 2014–15 season, Hernandez won the
grand slam with all stages of the World Para Snowboard World Cup in both snowboard cross and
banked slalom; leading her first full season gained her a Crystal Globe and she ended the season at
La Molina crowned world champion in banked slalom and with a silver medal in snowboard cross.[6] In 2015–16, still competing for the Les Angles team, she won 10 races in the European and World Cups and 2 further Crystal Globes — a gros globe for leading the World Para Snowboard rankings and a petit globe for first place in the banked slalom — as well as the silver medal for snowboard cross.[7]
On 4 February 2017 at
Big White, she won another silver medal in snowboard cross,[8] winning the banked slalom silver 3 days later.[9] At the end of the 2016–17 season the following month, with 7 spots on the podium, including 5 victories, she won a third gros globe and both petits globes for snowboard cross and banked slalom.[10]
She won the silver medal in the women's dual banked slalom SB-LL1 event at the
2021 World Para Snow Sports Championships held in Lillehammer, Norway.[14][15] She also won the gold medal in the women's snowboard cross SB-LL1 event.[16][17]