Do you think shes faking? ?

Okay so I had this "bestfriend" and we were like sisters. We were always together and had got along great. Occasionally we would fight and she would blow me off. & sometimes she tell me a little of something that happened or if I asked her a question shed be like I don't know. But then run up to someone she wasn't as close with and tell them right off the bat. Recently she said lets hang out this weekend. She blew me off yet again and I just got sick of her. She always tries to steal my friends and always copies me. Does my sports, switches to be in my group, and likes the guys I like. I got annoyed. We haven't talked for 2 days at all. You don't go two days without talking to your best friend. Do you think shes faking? Should I atop being friends with her and spend more time with friends I have recently(over the last few months) become close with? And should I reconnect with best friends who I was closer than her with before she ruined me and my other friend's friendship? Help me! Advice please! Thanks! Sorry its so long. And if she is, how do I stop being friends with her without being rude?