From an early age she showed talent for tennis, and her father Aimé Ngounoue helped her begin to train.

[citation needed] Ngounoue won the 2023 Wimbledon junior title, defeating Nikola Bartůňková in the final.

[5] On the ITF Junior Circuit, she climbed the top of the world rankings on 5 June 2023.

Ngounoue also won the 2022 Australian Open girls' doubles event, partnering with Diana Shnaider.

[6] She also won the girls' doubles title at the 2023 French Open, alongside partner Tyra Caterina Grant, against the top seeds Alina Korneeva and Sara Saito.