To be frank, it was indeed implied that she probably could see something was amiss but at its best, it was like trying to see through a thick layer of haze because of the surrounding environment being clogged by malicious aether from the nearby tower, thus obscuring her vision & effectively her judgments.
Heck, even back in ShB our WoL was carrying so much corrupted light aether that it virtually obscures our corporeal aether, making Y’shtola think that we are a Lightwarden approaching the woods.