What is she trying to do?

I share a room with my girl cousin. I completely dislike her. Maybe a little more than dislike. When she first moved in, she was pretty cool but kinda strange. As days went by she became a bi*ch, she'd like act like everything is hers. She tells me my decorations are ugly and she takes them off and put up her stuff. It made me mad, I'm just like thinking.. it still is my house whatsoever. I caught her talking shi* about me this one day, she was telling her friend how I was like stupid and retarded. I'm like wow. And I decided to never speak to her again. She makes me mad. She just like asks obvious questions. My whole family doesn't like her and her family. But we have to deal with it because no matter what, my uncle is my mom's brother.
I realized today that for the past three days she's been copying me. I had my pillow behind me at the computer and the following day she did the same. Then today she went shopping and got exactly the things I have.
Pisses me off how she's copying me. What is she trying to do? P*ss me off?
How can I deal with her?
I admit I'm rude to her, but that's only because she's rude to me. She like says hi to everyone but me on purpose, but when my parents are there she acts all nice and sh*t. She's such a kiss a*s.
Whateverr. I try to ignore her.
What should I do?

Maybe she's jealous of you so she's trying to copy you (why else would she be trying to copy you?)
I would just pretend she isnt there...

Punch her...

Speak to your parents about the problem.

Dear babyangel22,
I'm sure she does not want to be there either. I'm sure moving into someone else's home, someone else's bedroom etc. is very difficult for her. Copying someone is the highest for of flattery. She is lost in many ways. She is watching you for some direction into her life. I understand your frustration with her but this is where you, who has a home, a loving family and some stability must have some patience and some maturity here. Sit her down and discuss with her how you are feeling and ask her how she is feeling. You are both in a situation that only you both can come to some agreement with. For what ever reason she is there, she is not a mature a you and she is scared. Like it or not you have become her role model and she may just copy you when it comes to learning how to come to an agreement. Show her how to be mature and how to handle this.
Sue...good luck

wow, how is she alive?!! lol
if I were you, you could've found her dead from the first day!! lol
I would throw away her things and tell her it's my house, my room!!
but at the same time, you guys need to share your room! cause I don't think she has a room on her own, try talkin' to her about why she's doin' all this to you!
and if nothing changes, tell your parents about all this problem!!
good luck

She's probably mad at life right now and like the other person said a little jealous. Is she maybe younger than you? I've had friends that who were maybe even only a couple years younger than me still try to copy me. I don't know why girls do that. They'll buy things you said or wanted to get, like clothes or whatever and then act like theyr'e all the crap because they are wearing it, when it was your idea in the first place. I don't know why they think thats cool. It is really annoying I feel you on that one.

As for her being mean, she can't be mean to you forever. And whatever you do don't scream or be mean back or lose your temper on her. I'm pretty sure living with her and doing that won't make it any better. Actually it would defeat her if you just acted like it's not happening. What she is doing is trying to get a reaction from you. There is nothing wrong with telling her you don't like the way she's acting, but leave it at that. A long draw out conversation about it might just cause a fight. Wait it out. Wait her out. I'm sorry she is in your room.

shes probably copying you because your jelous, and she probably doesnt want to live there either