I want to tell my sister that she should pound sand.
Why do you feel mad at your sister?
She is so rude and made my childhood pretty miserable.
It is very rude to tell someone you want them to pound sand. This will only make your relationship more stressed.
Screw it, she is mean anyway.
Well telling her to pound sand is only stooping to her level. You are better off coming to her in a more composed manner to try and discuss how she makes you feel.