Miss Nord-Pas-de-Calais 2023 Gilles's first pageant was the local Miss Hersin-Coupigny 2023 pageant. She had aspired to become Miss France since her childhood, but was encouraged by her maternal grandfather to finally sign up to compete in a qualifying pageant. At her first registration, she failed to meet the height requirement of , as she was . She later reached the requirement through
stretching. The final was held in April 2023, which Gilles went on to win. As Miss Hersin-Coupigny 2023, Gilles qualified to compete in
Miss Nord-Pas-de-Calais 2023. Gilles won Miss Nord-Pas-de-Calais 2023 in October 2023 at the
Arena Stade Couvert de Liévin in
Liévin. She crowned her successor Sabah Aïb at Miss Nord-Pas-de-Calais 2024 in October 2024.
Miss France 2024 Gilles represented Nord-Pas-de-Calais and won
Miss France 2024, on 16 December 2023 at the
Zénith de Dijon in
Dijon. She was crowned by outgoing titleholder
Indira Ampiot of
Guadeloupe, becoming the fourth woman from Nord-Pas-de-Calais to win the title. After the competition, Gilles was the victim of
cyberbullying about her physical appearance, receiving negative comments about her hairstyle and body type. Gilles was defended by a number of French public figures, including politicians
Sandrine Rousseau and
Karima Delli. As Miss France, Gilles received gifts from sponsors, a year-long residence in a luxury Paris apartment, and an undisclosed monthly salary the equivalent of a
senior executive in France. Gilles appeared at a variety of events both in France and internationally. She was a guest in season 11 of
Star Academy,
2024 Series Mania, the
2024 Cannes Film Festival, the
2024 French Open, and the 2024
Monte-Carlo Television Festival. Gilles also modeled in
Barcelona as the face of
Festina and walked for
Pierre Cardin at
Paris Fashion Week. In December 2023, it was announced that Gilles would participate in the
2024 Summer Olympics torch relay, appearing in July 2024 in
Lille. In March 2024,
Gabriel Attal appointed Gilles as an ambassador of the
French government for mathematics, to promote further education and careers in mathematics for young girls in honor of the
International Day of Mathematics. Gilles represented France at
Miss Universe 2025, and finished in the top 30. ==Post-pageantry==