for some reason, when she is interacting with someone whose job it is to facilitate a purchase she is making (store employees, restaurant servers, etc.) she can be surprisingly rude. I am taken aback each time it happens because it is so out of character for her. I think it is how some people have been raised. It's almost like they are mad you are taking their money, like "if I'm going to pay you for this, gosh darnnit, you are going to earn it."