This is LONG..but serious?

Theres' this girl who used to be my friend in 5th grade. Well, we're in 7th now,and she's CHANGED. Today i wore a red sweatshirt with sequins in the shape of a star and some dude from the muppets on it holding drumsticks and it said " Born to rock" and she was looking at my shirt & my friends shirt ( my friend was wearing an All time low shirt) in disgust. She wears all that name-brand-stuff like Coach,Aeropostale,Abercrombie & Fitch,Ed hardy. My parents CAN afford that, its' just that i don't want them to spend 60$ on a shirt. That particurlar shirt i was wearing was from Wal-mart, but i don't really care, i liked that shirt. And she was like " Well, the clothes i wear are soo expensive.." And in 4th grade she lied and told everyone she was rich and had a mansion-her parents are divorced and she lives in an apartment. I never judge anyone financially, or by appearance. She looks at someone and makes the " that's ugly.." face. I was wearing nikes that were a gift, and she was like " Are those REAL nikes?" i was like '' Yes." and she said " Didn't think you can actually get them..from a store that's not walmart." My parents like to shop at Wal-Mart,Kohls',And jcpenny for me. Is that soo bad? I get self-concious about what i wear now because i'm going to wear a gray & white hoodie tommorow with a heart on the upper left with mickie mouse in it..It's just MY style and i can't even wear what i want w/ out her commenting me. I have air walk boots that look like uggs, but they're not. I'm afraid to wear those too. Is there a law i don't know of that says *everything* has to be brand-name..or your a loser? I know i get talked about in school, but it doesn't bother me. I have my group of friends who support me. What can i say to her? She's a label-? Well, We know that and i don't think she does. I mean, she get talked about like " she's such a liar". She was walking in cl today and was like " I got uggs everyone..not fake crap..real uggs!" Who cares? She's in the "group" with everyone who wears expensive clothing..some of the girls that do ARE nice..but not her..soo..what should i do?