Stick to your guns!!!! If you don't want her going to a party while she's visiting then let her know she isn't going and if she doesn't like it, well then she can't come visit.
There is no reason in the world for you to put yourself through this. You are probably just finding a little peace in your home without her living in it. You don't need to worry what she is doing and where she is when she's visiting.
Set the rules and tell her if she doesn't like it, you'll meet her for lunch sometime, but she can't come stay there.
