Spoiled Rich Kid vs Strong Smart Girl

Clothes, makeup, jewelery, money. Me and my sister get whatever we want, whenever we want. I'm 13 and so is Sasha, my sister. We aren't twins, like everyone assumes. I'm exactly 9 months older than Sasha and at the moment we are at a rare period of time when we are the same age.
Today, we wanted to go bowling, so our dad took us to the poshest, most expensive bowling place in London. He said he'll try and pick us up at midnight and if he can't, Anna, our stepmum will.
We're in the toilets, putting on our makeup and perfecting our hair, looking in the mirror to see if we look good. I saw this girl who was with her 3 friends in the toilet tell them how we looked slutty. She kept staring at me with beady eyes in the mirror. That's when I couldn't take it anymore. "Why are you wearing red, pink, black, green, blue, brown all at once? You look like a tramp," I said.
"Why you wearing so much makeup on your face?" She replied in a split second. I could hardly believe that she had tryed talking back to me.
"Why have you got a hairy face, like a monkey's bum," Sasha spat at the girl. I could see the girl raise her hand, ready to slap Sasha. That's when I kicked the girl. Really hard. I was wearing red heels. The girl fell back, and suddenly got back to her feet and punched me, right in the heart. I can't remember what happened next, as I was unconsious, but Sasha told me it was a bloody site, pulling hair and kicking, the girl's friends were just standing in the corner doing nothing while their friend was in a fight. "Really?" I said, amazed.
"Yeah. But the girl didn't need any help. She was really strong, I have to admit. She punched, kicked, slapped, pinched me. I didn't mind her beating me but I couldn't take it that she had punched you and made you unconsious. You were just in a pile on the floor. So I pushed her, hard against the wall. She slammed her head against the wall and was bleeding. Then I remember how she and I were taken away, by the police. Someone had phoned the police. Mary, I'm going to jail next month,"
"Wh-wh-what?" I said, stuttering and crying.