Daughters don’t speak at all

I have two daughters. One is a teen and one is a tween. They don’t speak. My teen says that she hates the tween and will not budge. This started about 7 years ago when my teen was 10 and my tween was 6. Somehow, normal sibling rivalry blew up into this situation where my teen refuses to be in the same room with her sister. And she speaks about her with so much hate in her voice.

On the one hand, this breaks my heart because this is not what I wanted for my girls. On the other hand, I’m very angry with my teen for perpetuating this situation and not caring anything about her sister.

I’m getting ready to have a family meeting about this but I don’t know if that’s the right decision because I’m angry. But I also bowie this needs to be addressed because its not getting better on its own.