I only read your post, and here is my say...say hello to your ex-friend!
You are very right, you and your family does not deserve to be treated that way. She is inconsiderate for not telling you that she is moving out of the room and especially for not telling you that she already had left for home.
A friend can talk to a friend no matter what. If there is a problem, she should have confronted you and fixed the problem, instead she gave you an "attitude" through out the entire trip. I know the trip was not a happy one, not if someone is a "grouch".
She didn't even bother to say thank you for inviting her to the trip. What is her problem? Anyway...If she doesn't call for an apology, then don't worry about it. She must realize that she has a problem and it sure is not your problem
I' sorry that your friend has to be like this towards you, especially that she has been your friend for so many years. Don't worry, it's will be alright. If she doesn't come around, then don't worry about it, maybe it's for the best.