Imagine that she is a roommate, but not a friend. (Because she is). Have you ever had a roommate with whom you were friendly, but not "friends"? You can say hello nicely when you see her, but you live your own life and do your own thing. And let her do hers. For ex: if you are going grocery shopping, you *could* say, "hey I'm going to the store, can I get you something? " (but you are not obligated to). But you probably don't say, "hey honey what do *we* need at the store?" Because right now there is no "we", and even though it is the hardest thing to accept, you have to accept it. And focus on you. If that is not yet your mantra, it probably should be!
Living in the same house will be hard for you. And it will be hard for her too. She may not be nice to you. You can choose how to respond--dont take the bait. It will only reinforce that she made the right choice. Set some personal boundaries, which you can do politely without seeming hurt.
Good luck.
Why do you have to tell her that you will meet her at the appointment? Does she know about the appointment? Does she have a means of getting there? I suppose to be friendly you could say, "I hope you settled in ok last night. I will see you at the meeting later." And leave it. You don't have to tell her what you are doing, and you don't have to ask about her.
