Sister help!!!!?

k,my sis has been weird lately.first she ignors my mom,then she gets pissy about how i take the fork from her(she was ping them out),then she is just pissed off at me for no reason.ex:(this really happened) i was putting up some clothes and she came in to the room to put up her clothes.i told her i would put them up for her but she says no like she is mad or something.and a few seconds later i asked if she wanted gum and she took it like she was mad again.after awhile i go to cheeck my mail and listin to some music.my sis was on and and told me about this song she herd,i ask if i could show her a song that i like and see if she would like it.she said NO,with out knowing what the song was(is was "have a nice day"by bon jovi).she adds to her comment"its probley stupid.like always!" i reply and say"its not!its by-"she cuts in and says"NO!forget it!leave me alone." is this the tylpical teen?i'm really concerned about my sis,i miss the playable older sister.