Maybe she just wants to be ur friend again, like I used to have a olf friend like that, but if u dont want to be her friend then ignore her, thats want I done and it worked out fine. Yes ik its VERY annoying that she tells everyone shes ur bff, thats what my old bff done and I just told everyone the truth- that shes really not my bff.
hope this answered ur question, dont worry too much about it, she'll go away.
awesomeyamema