Zelda wasn't sure how to react. She read enough into what was said to infer that the cook had been connected to Monari somehow and she'd just already had crow for breakfast. But atop of that, Monari's lack of recognition of her... what did she mean by that? The princess liked to travel? She'd just told her what she liked.
Maybe it was just a gracious way to avoid getting bitched out for insulting Monari's mother. That was more likely. Everyone knew she'd been keeping Ganon contained all this time, right? How else was it that he never had a chance to devour the land and was forced back so deep into the case that it became safe for grave-robbers and looters to risk their necks? She was only vaguely aware of it, and there was nothing that she could do to stop it. If she gave him even a fraction of a purchase back then, it would take all the more energy to force him back under her control, and she wouldn't have been able to hold out long enough for Link to arrive.