My niece is a brat that does whatever she pleases?

K'so i'm currently living in my cousin's house and he has a 12 year old daughter that always gets her way.
She talks back to her parents, doesn't obey rules (ex: if she is told to get off the computer at a certain time she does get off but when she knows that her parents are already asleep she uses it again). They have a two bedroom apartment and i sleep in the living room and the computer is in the living room so i don't really sleep throughout the night and she knows i have work early in the morning. Her parents talk about this to her and she says ok and a few days later she's doing it again and they don't say anything. She never gets grounded and is about to get a new phone after she lost her iphone a few days later after she got it. So basically she does her parents how she wants. I know that i'm a guest in their house which is why i haven't confronted her or her parents about this but i really can't take it anymore.also, i can't move out because i just came to this city and i haven't gotten a job yet. I'm using her Yahoo answers and i know its wrong but i don't have a yahoo and she leaves her account on so i thought "hey. Why not?".so please answer and tell me what i should do about the situation.

I don't know, but she can see this answer if you don't delete it.

Uh… Why do you think you can do anything about this situation? You're a GUEST in their house. You're not her parents. And her parents don't discipline her so that's why she's like this.

You can't take it anymore? THEN LEAVE! Othewise, keep your mouth SHUT!

  • Why did she give me her number if she won't respond back to me? I met a really cute girl last night and started talking and she was like I'm about to leave take my number so we swapped number hugged and she left and was like text me. So today I text her and saw that the text I sent was read (we both have an iPhone) and she never responded. She seemed interested in me. So i don't know why she just read my text and didn't text me. Why did she give me her number if she didn't reply to my text?
  • Why did she call me a spoilt brat? So today I was out with my friend (let's just call her Hattie for this) we came back to my house to get changed for a party and she walked into my room and saw that I just got a new camera and a new iPhone 4S then looked at me an rolled her eyes but I just ignored it then she looked in my wardrobe for something to wear for the party but she couldn't find anything so I told her to look in my other wardrobe then she called me a spoilt brat, just like that
  • Why did she call me a spoiled brat? So today me and my friend were at mine getting ready for a party and she saw that I have a new camera and iPhone 4S as well as new art supplies and se pointed out then rolled her eyes and told me I don't all this stuff (I'm going to study art and photography at college and she knows this) I just sort of brushed it off then she couldn't find anything to wear in y first wardrobe so I told her to look in my other one then she called me a spoiled brat and stormed out.
  • What does it mean if you are a spoiled brat? Everyone says I'm a spoiled brat because I got an iphone 5 the first day it came out, I have an Ipod, kindle fire, iPad, and blackberry if my iphone breaks. I have a lot of clothes but I mean, doesn't everyone have that? That's normal right? So I don't see why people call me that? And I'm only a brat if you are not my friend or if I'm in a bad mood.