So hit her back it's not a one way street

Punch her back. Simple enough.

It's presumably a little sister so yell at her. You don't get physical but you get the message across halfway peacefully.

I would punch her back. When I was little my brother and I would punch each other all the time. I'm female and I realized that if I punched him, he would punch me back. Siblings fight. You just have to stick up for yourself.

Okay, I have a little game I'd like to play with your dad. Get him here and make him look at this comment. I call the game 'Flip the Pronoun'. Here's how you play: take all the gender-specific pronouns in a sentence (he, she, boy, girl, etc.) and flip them so that they reference the other gender. If the sentence makes you feel any different, there is something wrong with the way you see the world.

Punch your sister in the face and say "equal rights!" (Don't do that)

Unless she's a child, hit that notch back. Equality.

Grab her by the boobs and slam her down really hard on the floor nothing like a little sibling fight every now and again

Make all of her barbies look like war victims. That'll teach her. Or turn your forehead into it and watch her break her hand. That works too

That's also totally sexist against women (as well as men). F her life