I'm going to leave my friend out of a my party that the rest of our group is going to.
Why would you want to ditch your friend like that?
I don't have reasons for this, I just hate that girl
If you hate her, is she really considered a friend? But in the end it's your party and you can invite whomever you want. Do you think you'd want to try to make up with her in the end?
You sound like a cultural marxist
Why are you even inviting her to the party in the first place? It's fine if you don't like her. Just don't invite her if you're planning on ditching her later.