Self government

My 10 year old went away with her dad this weekend and he came home completely discouraged. She was rude and demanding most of the weekend. Telling him she was hot or cold and whining much of the weekend. The final straw was when she was hungry for breakfast and wanted to go down to the lobby to eat. My husband said she could go down with her older sister or wait for him to brush his teeth. She promptly told him she no longer wanted to eat and refused to eat all day. She is 10 years old and not even 50 pounds. This is not the kind of kid who can skip a day of eating but you can’t make a giant deal out of it or she will continue the behavior. How do you use the Rule of 3 or teach self government in this situation?