She using me or being a bish?

I have this friend named Diamond who is dating my cousin I don't really like her anymore because of these
1) always bossing me around
2) always trying to smack and kick me to show off
3) hangs around me when her best friend Karina isn't there
4) pretends like she knew me longer than anyone else
5) when I have led pencils she always asks for some then takes led out of the rest of the pencils or the erasers or the rubbery at is at the end.
6)always going in my backpack for lotion and lets others use it
7) Takes my erasers
8) uses my sharpener without asking
9) takin my paper so she can copy down the answers (I change it to the correct once because I know she will copy lol)
10) Pretend like she doesn't know me around her other friends
11) FACETIMES me (we both have iphone 4's) when she is bored
12) try to say I copy her style when other people had it first
I do to to my principal and teachers to talk about it but all they say they take bullying serious but they don't! I'm sick of it. I was going to say I'm not her friend but then I don't for my cousin because he really likes her.

Just cut her out of your life!