Wait...she didn't feel like 'staying' for it? That would imply you were not her only appointment and she had already come in for others. Were there several hours between her earlier appointments and yours? If you were her only appointment of the whole day, I would assume she would have never come in at all if she was going to be so unprofessional as to cancel you for no good reason.

I would find it unacceptable. I'm sorry that happened to you.