The Great Gatsby, inquired Daisy coldly

Could you please tell me the meaning of "coldly" in this excerpt from the first chapter of The Great Gatsby?

“Good night,” called Miss Baker from the stairs. “I haven't heard a word.”

“She's a nice girl,” said Tom after a moment. “They oughtn't to let her run around the country this way.”

“Who oughtn't to?” inquired Daisy coldly.

“Her family.”

“Her family is one aunt about a thousand years old. Besides, Nick's going to look after her, aren't you, Nick? She's going to spend lots of week-ends out here this summer. I think the home influence will be very good for her.”

Thank you.