Did you have a confirmed AW booking with her? Did she ask that you reconfirm on the day or anything like that? Did she provide you with any reason as to why the booking was cancelled?
I ask because she has another job outside of AW that is customer focused, and for her to just cancel without any explanation doesn't seem right. I'm not disputing your point of view of what happened nor defending her actions, just trying to fill in some details.
If you had a confirmed booking, you followed her procedure, and she cancelled at a moments notice without any explanation (read credible explanation), then that is defo a big negative.