Notably, Maryam Mirzakhani is the first woman to win a Fields medal. https://en.wikipedia.org/wiki/Maryam_Mirzakhani
Also notably, 1. Mirzakhani is the first Iranian 2. Bhargava is the first Canadian 3. Hairer is the first Austrian 4. Avila is the first Brazilian
So, I understand instead that you're identifying this as notable for the following reason:
There are 100 times more women in the world than Canadians, yet women and Canadians have the same number of Fields Medals.