Oh wow! Why are YOU moving again?? Is it your house? Why can't she go live in the summer place? Even though she may not be using, her attitudes and actions are unacceptable. She should feel very appreciative that you allow her to stay with you at all. Her recovery is her own, and she is going to have to learn that the world does not revolve around it. If you want your relatives to come for lunch, then she should just deal with it or arrange to be gone during that time.
If she wants recovery, she is going to have to realize that she is going to be faced with many situations that she might find uncomfortable, but she cannot expect everyone to rearrange their lives just to suit her. So, to answer your question, yes, I believe you are enabling her by moving out and also by allowing her to cancel plans just because she wants to.
You cannot help her get stronger. That is something she must do on her own, and facing situations that aren't exactly to her liking is just part of it. I can't tell you what to do, but if it were me, I would not move, nor would I allow her to be disrespectful to me in my own home. If she isn't happy there, then she needs to be the one to make alternative arrangements.