I do not think you were overreacting.
Does she make a habit of doing this to you?
Hi - I replied on the Toxic Relationships board.
I don't think you're overreacting. Your friend's behavior was very immature, to give you the cold treatment for 2 days because you were not available to entertain her 24/7. It sounds like you did plenty to show her a good time, and like others have mentioned, she is an adult and could have gone sightseeing by herself if it was that important to her.
As for what to do now, that's really your call. If you feel like the friendship is beyond repair, then try to let it go. You shouldn't have to put up with people who treat you like that. And if a part of you wants to salvage the friendship then call her and try to talk it out, let her know how she made you feel. If she accepts responsibility for her behavior and apologizes directly (rather than on a card with flowers) then maybe you can patch things up. By her reaction you may know if there's still a friendship left.
If you don't feel like you're getting the reaction you deserve, then you're better off without her.
Thanks for your feedback everyone.
I wouldn't try to hash things out via email. Too much chance for misunderstandings. While in person would be best, over the phone is next best. Tone of voice can make a big difference in how a person takes a comment.
It does sound like you and she have gone in different directions in your attitudes and approaches to life. Before she started acting all pissy, were the two of you having fun? Was it like old times? When you were at your home/with the family (ie. your real life) vs sightseeing was she fun?