[1] She set a new French national junior record at an event in Argentan in 2014, with an attempt of 13.74 m.[1][citation needed] Diallo won her first major medal at the 2014 World Junior Championships in Athletics in Eugene, Oregon.

She broke her own national junior record twice during the event, landing a 14.24 m jump in her first attempt with a 3.2 m/s headwind.

After a foul in the second round, she jumped 14.44 m with help from a 3.3 m/s headwind, an attempt that was enough to win her the gold medal.

She became the third French triple jumper to win a world junior title for France after Benjamin Compaoré in 2006 and Teddy Tamgho in 2008.

[3] Diallo is mentored by fellow French triple jumper Teddy Tamgho, who is the current triple jump world indoor record holder at 17.92 m.[2] She currently trains at the Nice Côte d'Azur Athlétisme club in Nice.