Is it normal to hate your ex best friend?

Ok so last year she was somewhat nice to me still but didn't really hang out with her. But now this year she acts like a total snob to me and my new friends.

For my birthday she couldn't go to dinner with me so the rest of that week she kept tellin me that she wa going to give me the biggest present ever. Have never gotten it but I would at least like a sorry for telling you that but I can't give you a presen or something.

But she became more of a bitch to me and especially those who are still my friends (only when they are around me. She sometimes just tries to take them away from our conversation) after I could go to her birthday thing beacuse my cousins came from Germany to my uncle's wedding that month

So is it normal to hate her now?