I find this point really interesting. First of all, she did not throw on "old clothes". She put on a very nice outfit that I am sure she selected with Christmas in mind, because she was that kind of woman. No inference meant there, i am as well.What would be on your mind if you were waking up planning to go on a vacation that morning? The vacation. With that in mind, how would you dress? Would you just throw on the same old clothes you wore yesterday or would you dress for the vacation you were taking that very morning? Answer that question for yourself
She was not dressing for the entire vacation. She was dressing for a plane ride and she would have met up with the adult kids and the fiance'. None of those people had seen her wearing that outfit the day before.
Sorry, I just don't see the big deal on that. Never have.
Now, does that mean that she did not have the outfit on because she was not up all night staging? Nope, not IMO. That may well have been the reason.
I just don't see that that outfit, in and of itself, means anything one way or the other. Same with bad manners on the car ride.