From Wikipedia - Simple English:
"Only 13 female figure skaters have done a ratified triple Axel in competition: Midori Ito (the first one to do it), Tonya Harding, Yukari Nakano, Ludmila Nelidina, Mao Asada (the first one to land three triple Axels in one competition), Kimmie Meissner, Elizaveta Tuktamysheva, Rika Kihira, Mirai Nagasu, Alysa Liu, Ayaka Hosoda, Alena Kostornaia, and Young You."
This is only taking into consideration skaters who have landed 3As in international competition. I realize that to be officially counted, that's what has to happen, but there have been plenty of other women who have landed 3As domestically or in practice, if you want to get really nitpicky.