Nobody briefed her for this, she thinks in fleeting panic -- should she repeat it after them? Will it be considered rude if she doesn't? Or if she does?

What decides her not to repeat it is that she doesn't know what it means. Instead she smiles again, and makes a half-bow while gathering up the menus, and slips off to deliver the orders.

(And if her heart's thumping like a triphammer, no one else can see that.)