You guys are absolutely right. A friend of mine said, and I believe it to be true, but by protecting and sheltering my sister the way they did, she has no sense of the reality of the real world and has this false sense of entitlement.

As for my mom, she was very upset and vowed to avoid my sister at all costs until they move, maybe longer than that. She defended herself and kicked her out of her room.

It's just a bad situation and honestly, once I leave, I am gone. I know there are people out there with no family and I feel guilty that I am throwing away mine, but having her in my life is detrimental to my mental health.

Thanks so much to everyone who posted, I have a lot to think about and a lot of work to do to move out soon.