She can withdraw privileges like internet access. She can force your sister to stay in her room and eat separately - to give a signal she's not welcome to be part of the family if she's going to act this way.

Exactly. This is what upsets me.

My mum just gets so frusterated and upset and stressed she just fizzles up and tells us to stop and goes on about how I'm ruining her day, or how I'm older and I need to stop.

I'm ALWAYS the one to blame. I'm always going to be the eldest. That doesn't mean she should get away with everything.

It's not fair.

They treat emotional abuse as perfectly fine, but a slap in the face / wack on the arm is just CRAZY and NOT OKAY at all, and everyone has to threaten me and make a big giant fuss about it and tells ME to stop. It's kind of ironic coming from a household where their children were hit, and my father use to pretty much physically abuse me.

Even when I say some insult back (I never ever never never say ANYTHING back or do anything unprovoked, I swear to god, I swear to the universe), my mum will tell me to stop but not her.

Everyone's always pissed at me.

Now that I think of it, sometimes my mum does say "go to your room" to her, but she just responds with "no". And that's that.

That's what frustrates me, my mum could say "stop that right now, stop speaking like that" and pretty much get her to STFU, but she doesn't do ANYTHING LIKE THAT.

God, it's so annoying, which is why I get angry.

Yes I sometimes hit because my words don't work, no one is making her stop, so my logic is to use my hands to make her stop hurting me. Which is bad I know. I should just walk away.

Thank you very much.