Snowball meta

If she plays right against Fiora, possibly yes.

For Illaoi, if she doesn't play stupid, definitely yes.

Quinn has always been among the strongest duelists in the game, and although her Q doesn't hit melees as hard anymore, she still has the kitting, damage, and outplay potential to play against the other strong duelists.

Illaoi is a juggernaut, an entire class which is among the most vulnerable to kiting. So putting her against a champion the excels at fighting kiteable melees even more so then a lot of other ADCs, it's pretty much no contest.