I could use some help with dealing with my ex girlfriend.. and her friends...?

[Rose]

Fighting back would probably make it worse and cause more drama, which is probably what you don't want. The best thing I think to do is just ignore the girls, because they sound like idiots and are just doing what immature girls like to do after a breakup. The best revenge is to forget about her, pretend like she doesn't exist and move on. If you think she checks your Facebook, then post pictures of you having a good time with your friends or other girls. That'll show you're ignoring her and don't care about what she's doing. if you don't want any hard feelings between you two, wait a few months before you try to talk to her, since the breakup is only recent.
Really, just ignore her and her friend. That's really the best revenge you can get.