Should i cut her off?

Okay ladies, i know I'm probably gonna get judge alot by this but just bare with me! So i had this ex i was with for 3 months long story short he had this crazy ex and he cheated on me with her while we were together. She ended up calling me and telling me everything. But we decided we weren't gonna hate each other because of a boy. Mind you guy's I'm 17 she's 15. Anyways we end up becoming really good friends i would go over to her house we did like the normal girl stuff. Well after i got over what my ex did to me i met this new guy named Josh, josh was a very good guy we had a good time but the only problem was this girl! I would tell her I'm going to his house or whatever and she would just call me phone blow me up on Facebook she did the most ladies! And when i would answer she would just tell me her problems or tell me to tell Josh to take me to her house omg it was so annoying!! Me and Josh ended up breaking things off to. Now I've been dating this new guy and this girl knows who he is because they talked awhile back but not like serious talking or anything. But yeah my boyfriend told me he didn't like her she was a bitch he didn't like her attitude etc. Well one day i was with him i hadn't seen him for a whole week, mind you guys i had talk to this girl every day! Well i was with him and i guess she called and i didn't answer so she messaged me saying "oh that's fucked up just because your with him doesn't mean you have to ignore me" girls i lost it! Like wtf what kind of friend does that! If I'm with him then I'm busy of course I'm not gonna be rude and be on the phone the whole time because your fucking sad. And i showed my boyfriend and he was like wtf does that bitch want tell her to leave you alone. And i didn't talk to her after that until yesterday. So before me and my boyfriend started going out he had this picture of this girl for his wcw (women crush Wednesday) and so she messaged me and was like "ayyy" and she sent me a screenshot of that picture and asked if i had seen it i told her yeah, and she was just like "ooooh.. Are yall still talking?" i was like wtf? Frist off what the hell are you doing creeping on his facebook page for? And second don't worry about it. Now I'm getting tried of her shit. Do yall think i should cut this girl off? Is she being fake? What should i do.