You're not her best buddy. You are her mom. Try at this point to be her chum and you will end up with her hating you for it.
Does she have any activities other than going to school? If a kid is busy they cannot get into trouble and don't have time to think about acting out; if the activity is a good one with strong adult role models, the kid also does not talk back because the activity reinforces that respect, not talking back, is what's right and expected.
If she does not have an activity or several, it's time to ensure that she is too busy, with the right kinds of adults and kids around her, to want to be on Facebook or seek out her problem friends.
Talk to HER an make it positive. Do not present it as I have here -- that's mom talk -- instead, tell her that you would like her to choose some activities that she really, really wants to do and stick with for this school year. I would avoid activities that are closely tied in to the school culture, such as sports or cheer, for now at least; she needs something separate from school so she can be her own person and is not encountering kids who know her from school or who know her friends.
What might SHE want to do? Art classes, dance classes (be careful to choose a reputable studio and I would avoid competitive dance at this point--she needs reinforcement of her own abilities, not competitiveness right now), archery or tennis or golf or another solo or near-solo sport that she can do on her own or with one other person, a book club....
Volunteering can have a very positive impact and keep her busy too. Libraries need teen volunteers all the time. Food banks are desperate for volunteers in many areas. The Red Cross and hospitals need blood bank volunteers. If she has even one good friend whom you consider a positive influence, see if the two of them can volunteer somewhere together. Volunteering teaches a kid to get outside her own little world where she's the center of everything and her own emotions rule.
Keep her too busy with positive activities to be around guys for a long time to come. As for school work, set up a schedule with her and yes, give some rewards when she does certaiin things by deadlines.