Here we go with the respect thing. Sleeping in the nude (panties only) is an issue of comfort when you're the only one in the bed. Granny is way too prude and needs to learn how to pick her battles. Really, is this the biggest problem they have with the girl? Granny also didn't mention if they lived in an earthquake zone. If it's that dangerous that she worries that her granddaughter isn't dressed to get out of the house in an earthquake, she should move to a safer area. What a numbskull. Let the girl sleep the way she wants and worry about the big things like training the girl to never start smoking.