third party

there's this girl who was my friend who I went to school with who's been stealing my crushes, boyfriends, friends etc. and I don't know what to do about her, she's just always there, and I don't know what to say to her but I gave her a warning and she accepted it but she still keeps interfering with my relationships and friendships and familial relationships. after my ex boyfriend cheated on me with her I can't trust guys anymore because she's always around me and them and I deleted and blocked her contact but she still talks to me in real life. I really need some help with getting rid of this girl