Our 17-year-old has to leave for the airport at 6:30 in the morning. After a day full of social activities, to which she wanted to add even more, we let her know she needed to come home and get ready for the trip. Despite having been home for six hours, when I passed her bedroom after midnight, she had not yet begun to pack. We have always modeled responsibility and preparing for trips well in advanced but she became infuriated when I said she needed to begin packing now, exclaiming she can manage her own time. How do we handle this now and make sure we're not repeating this lack of discipline on her part in the future?