How can i tell this girl to SHUT UP?!?!?!?!?!?

Ok so right now im at my aunts house. There is this girl and she is really ticking me off. See it all started when i was watching tv. Then this girl lets call her Briana. Well briana starts singing a little verse of a song out of nowhere. Its not that she sings bad it just that she seems to be forcing pion into her voice a bit?!?!?! IDK its hard to explain but she doesn't sing good. So i think she is trying to impress me with her singing "skills" or something? So I continue to watch tv and she sings another verse, a little louder. Im getting a little annoyed so I get up and leave to another room. Briana comes to the same room after a while. I was on the computer. Then AGAIN she lets out this other verse of a song. And this other girl whose in the room with me gos "Briana you sing really good!" and Briana just smiles and says very over sweetly " no I dont sing good." then she lets out another verse of a song. Im really annoyed..... so i go to youtube and listen to mariah carey. Then briana says in the middle of the song. " she messed up right there." I look at her like she is crazy. Mariah is a pro at her vocals and this armature is critisizing her?? "I dont think she messed up at all, Her voice is really pretty." i say. She gives me a snooty look and says " I can tell." i cant stand to be in the same room with this girl but she is following me around everywhere i go singing annoying versus what can I do quick?!?!?!?! I barely had enough time to type this before she comes in and sings another annoying line!!!!!!