Najeela and Annie Joins Up

[[Najeela, the Blade Blossom]] states that whenever a warrior attacks, you may have its controller create a warrior token that's attacking. [[Annie Joins Up]] states that if a triggered ability of a legendary creature happens, it triggers an additional time. I'm curious how exactly these two interact with each other. Is Najeela triggering off each other warrior, and thus creating twice the number of tokens from Annie Joins Up?? Or is the ability specific to each warrior while Najeela is on the board, and, in order to get the additional trigger from Annie, I need to attack with legendary warriors?