Revenge on little sister? rEaD!?

okay well im sick of my little sister getting whatever she wants. She is a little brat and I mean it, i am not just saying that. She gets whatever she wants and I don't and everyone babies her. I'm the oldest and I know i'm not supposed to act like a kid anymore but my mom doesn't even think I have responsibility when she thinks my little sister does. She is in kindergarten and I know this might sound stupid and all but I mean it. She was sick yesterday and today she feels so much better and my mom still makes dumb excuses because she was only sick yesterday. Does anybody know I can get revenge on her like I mean it everyone babies her and i am soo sick of it. Best answer gets 10 points..