controlling??!

Well... I had a past relationship with this guy, I thought I was truly in love with him but he played games and ended up just using me for sex now a year and a half later I'm in a new relationship and happy , I have a best friend that I told about the guy and how much her had hurt me and broke my heart and that I pretty much hate him, a few months later I find out that him and her are talking, being friends and being buddies , this broke my heart since she was my best friend , I confronted her about it, telling her that is hurt me and I wasn't okay with it , she proceeded to tell me that I can't tell her what to do and ect, and was defensive and always talks about him when I'm with her, does this show that she is a bad friend or am I just over reacting??? Please help :(