You won't believe this! This is worth looking into (Sivir)

Sivir will not gain any stack's of fervor of battle while using W (if an enemy champion is tagged by ricochet, sivir doesn't gain any stacks of fervor! zilch! none!

I tested this to see if she would gain stack's each time ricochet hit (like an auto attack) or if she would recieve stack's every couple seconds (like an ability causing damage) To my surprise, she simply doesn't gain any.