One of the people escorting the ever-more-crystal-covered Katara and Sokka around the crazy king's palace is a woman. Katara isn't sure if it's that that makes this guard seem less intimidating than the others—in fact, Katara rather hopes it's something else entirely—but whatever the reason, Katara has the nerve to speak to this guard, not the others.
"Is there a queen of Omashu?" Katara asks.
"No," says the woman. "There hasn't been in a long time."
So much for hoping this city has someone sensible who can rein in the crazy king.