She laughs, as melodious and light as ever. That's only the appropriate response to such an inquiry, to treat it as a joke (of course, it's a legitimate concern, Brienne is right to worry, but if Margaery let that show it wouldn't end well at all).

"It's a lovely city," she says, which isn't entirely an answer. "We've been warmly received, and I hope I can pay that back many times over."

She's skilled at the art of tact.