It's okay for me to shout at my mum after I'm done doing all her work, right?
I assume you're mad at her?
I'm angry at her for paying me less than she pays my sister.
Did your sister do more work than you? If not, instead of shouting, politely ask your mother why there's a pay disparity.
She shouldn't pay me less because I'm a boy, it's not fair.
You may feel better about this if you politely ask her about the pay difference. You may be surprised to learn that your sister does more than you do, or that maybe your mother wasn't aware of how much you actually do. I'm sure there's a reason that can be worked out.