Like her gratitude, it sounds sincere. Alina doesn't like how bitter that makes her seem, though. She doesn't like making Zoya the reasonable one, the right one.

And yet when she searches for something to say to make up the difference, Alina just says, "You'll be fine, here. All it takes to keep the monster at bay is to find someone to tumble."

It would have been better, she thinks, to point out that everyone is in the same boat, and Zoya is plenty attractive, and she has no hangups holding her back from that kind of thing. But no. Alina doesn't mean it that way. She twists the knife for no other reason than it is in her hand and Zoya's venom when Alina had first arrived at the Little Palace has not left her.