Can I avoid my non-muslim sister who argues with me?

me and my sister don't have a good relationship and I doubt will ever have one and I don't think I want to have one with her. she as vitcim mentally and she not muslim and it feels like she wants my family to become more liberal muslim. we arug a lot. we had a big fight today and honstanly i don't even want to talk to her and though it's mainly my fault and I can forgive her and myself but won't forgive me even if i tried. I know in Islam you shouldn't be upset with you someone for more then 3 days and that cutting tries with famliy is haram but i'm so done with her and her belifes and attuided and they way she want to change everything. please tell what i should in the best islamic way