Why does my mom baby me so much?

Okay for the past two years my mom has treated me like a little kid. She kept buying me training bras till I was like 12 and I'm a bit busty and she knows that and she kept getting me these uncomfortable bras that were 2 cups too small, she bought 30A's and I went to pink and got measured and I ended up being a 34C. Then she won't let me get a job, but when my older brother was 14, my mom made him get a job and she didn't care that he had one. Then she freaks out about letting me stay home alone, I'm not a bad kid, we live in the suburbs, we have a freaking alarm system and if I needed something I could walk to my neighbor's house or call my mom/dad/brother from my cell. PLUS ITS LEGAL WHERE I LIVE! Then she barely lets me out and when she does its only for like a couple of hours. I'm 14 wtf am I gonna do with a couple of hours. Then she gets mad when boys flirt with me, it gets on my nerves. I might not even think they're cute and she thinks I'm ho-ing around with them. Then she won't let me wear make-up, not even a little mascara. Once I wore a tiny bit of mascara and my mom got so pissed, she made me late for school. Then she doesn't respect my style. Like my decor in my room, she always rearranges it in the way she finds livable, well I'm weird and I like my living space differently, she didn't do this with my brother. I dress a bit 'scene' if u may stereotype me and she hates it! She hates my clothes and tries to put me down like saying they make me look fat or I look dumb or something, yet with my brother he was into the hip-hop style with the du-rags and the baggy a** jeans and he was super skinny, the white tees and the Jordan's. she had NO problem with his style, and he looked like a retard but everytime I said that she yelled at me and when he did it she didn't say a thing but 'Toughen Up, don't be wimpy. Ignore Ryan(my bro). Then she freaks when I text/talk to my guyfriends on the phone. I'm not ually attracted to them, and I'm not a promiscuous girl so my mom should trust me. But when my brother had girls calling him that were more than a friend t 14, my mom didn't care, she even let his friend Jenny come over and play bball. If I invite a guy over they say no. She won't let me chose ANYTHING! The way I do my hair, oh she even still does it for me when I tell her I'm capable of doing it myself. She cleans my room when I don't ask her to and when I tell her to get out she yells at me. I have like no privacy, my dad goes through my computer when I'm not home, he searches my shopping bags when I get home, EVEN IF I HIDE THEM IN MY CLOSET! and my mom doesn't say a thing! If it was my brother she would have yelled at my dad for being a stingy potato! She ALWAYS gets in my face about my opinion on things like music. I'm obsessed with Eminem and I really wanted some beats by dr. dre, she got mad and called me a groupie and that if I keep 'worshiping' eminem I'ma be a pothead just like him. I corrected her about the types of drugs he used and she just got mad. I'm very responsible and smart and fun loving. She doesn't respect my hobbies. I really love modeling and music but she doesn't want me to fulfill my dreams of being a singer/tv personality nd she tells me I suck at it when Ik I don't, I have some opinionated friends and they even say I'm talented. Yet when my brother wanted to be a gangsta rapper and he sounded like Lil Whyte she supported him, now he's an unrecognized DJ when he should be focusing on college, he might get kicked out and she thinks I'm the rebellious screw-up. Then she said that I'm a 'fake a** poser' because I wear jewelry with handcuffs, br knuckles, guns, skulls, hello kitty and cute cartoons. I've worn this kinda stuff for like 2 years and I've always been a bit weird, she wants me to be a preppy b*tch like she was in high school. I have plenty of friends so I'm not like socially challenged or anything just not like her. Do you notice the contrast b/w the way she raised me and my brother? btw he's 7 yrs older than me.