What can i do about my little sister...?

Well I'm older than her, and she gives me attitudes whenever i look at her an she always tries to make me look bad in front of people. She thinks she's the chit, and better than me.e don't get along like sisters.We can't even have a decent conversation, b/c if i start a conversation with her she will give me an attitude and say something rude to me.Every other pair of sisters that i meet are always best friends an have each others back.But we are different.We are like enemies.But not because of me, but because of her.I want us to be cool with each other and get along well, but i know that wont happen because of her bad attitudes, and her need to always making me look bad in front of my cousins and family.What should i do?I mean, i jut want her to stop making me look bad all the time, and you stop giving me bad attitudes for no reasons.Because i never do nothing to her.She does it because she hates on me probably.Should i just ignore her, and stand up for myself and set her straight when i have the chance, or do you have a better solution?(She's in the tenth grade by the way, an I'm almost in college in a few months)