L.D.
Your daughter needs to stop hanging out with this girl if she keeps getting into trouble when she is around her.
Talk to the school and have her switched away from the girl at lunch.
I dont know about facebook but, if I were you, I wouldnt put a whole lot of effort and energy into helping your daughter solve the facebook problem - put the onus on her to figure out how to get her facebook page reactivated. That's her "natural consequence" for engaging with this girl. Worse case scenario is that she isnt on Facebook socializing anymore (which is where some of the social drama originates).
As a former teacher, every year I saw girls - "frenemies" who were good girls, but were drawn into drama and "messiness" with each other constantly. One mom would come to school and talk about what the other girl did, and then the other mom would come and talk about what the first girl did - even if I put the girls on the other side of the classroom from each other, someone would be upset daily for an eye roll or a comment made. In these situations, I NEVER saw a time when there was one innocent girl minding her own business and another girl instigating everything.
The best bet for your daughter would be to just ignore her and NOT let herself get pulled into any more drama. Your daughter's job is to go to school and learn and do the best she possibly can in her classes. If she lets herself get sidetracked by middle school drama, she is short changing herself and her future.
Ugh! My daughter is 2 - I'm not looking forward to middle school! Good luck, Mamma!
Edit to add: The friend "hacking" your daughter's facebook account is probably a clear violation of your school's Acceptable Use Policy and should be brought to the attention of administrators. Just curious - how do you know that the "friend" did this? Did she tell your daughter or brag to other students? That kind of behavior is taken very seriously by network administrators - also - if you have any proof - you can probably report it to Facebook and the "friend" might have her account yanked...