She allows Tyria to have the last word, not because she's a pushover, but because she's much more interested in watching Avalon be. The woman is an enigma, and a disappointment. A Guardian with a blown cover. And one that destroyed the foundation of the city without rebuilding. There's something to be said for cleaning house, but the best disguise is one that can keep its cover.
Failing to keep up appearances is the best way to blow that cover. It's sort of like walking into the waiting room in the Kremlin after being in deep cover in the Soviet Union for two decades and screaming in a Texas accent 'I'm an American Spy!'. Maybe not that obvious, but when there are pieces missing and there are no attempts being made from the top of the organization to keep the organization moving, there's a fundamental flaw in the structure.
So inevitably, Nous is fascinated by the flawed personage of Avalon. She's not any more disappointed in her than she is in the rest of the so-called leaders who have done nothing to maintain Supernal order. That includes Tyria, and Ariadne, and the lackluster Ladder. The Freaks are the only ones that are true to form, excepting there aren't any that have sat down to create their own democratically appointed government. True to form in that they're misguided (useless?) at least.
"Manners."
She might be responding to the man called Crowley that was vaguely looking in her direction, but perhaps not talking to her.
No, she vaguely cares. She's much more interested in the mask that Avalon is wearing. Her instinct tells her that the woman they see is not the woman that is.