I do not think any of us can actually be "friends" w/someone in crisis...but that doesn't mean you can't be friendly/civil. I wouldn't tell her you aren't going to be friends or do anything for her...rather...when she asks you to do something, just tell her you don't have the time at the moment to help her out. You can do this in a nice way so that it doesn't appear that you are punishing her for her decision to move out.
Always, always remember...actions speak louder than words.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.
