If you want to see it from a friend point of view..

* getting together is a bad idea as it would not be a clean start and it's too much of a messy situation, if you care about this person and have a hope for something in the future you want thing to be clean and open. Also time will tell you if this is an attraction, crush, if she's looking for an escape or for help etc.

*she's your friend, and it sounds like she's young and stuck in something she isn't ready for. I would be honest with her and tell her to seek out for advice, speak to a friend (your sister maybe) and she needs to clear her head and feel some support. She might want this but just feels suffocated.

So I guess in short my advice is: keep things respectful, tell her she needs to take some time and ask herself if she really wants to do this regardless if you two had had that weekend. In the meantime you can get some prospective and clear your head.
If she's just got cold feet it will give her time to evaluate things and if her intention was to mess you around so won't be able to.
Good luck!