Friend trouble!!! Pls help?

Hi. My problem is there is my friend called Susan. I don't know what happened to her. She is just jealous of me. She gets angry if i do good in sports...and i m good in it. Everyone says i m athletic...she also gets crabby cause of that. Now she is copying me. I have cut my hair short, she has also cut it the same way. She never hang out with me nowadays. Instead, in front of my house, she plays badminton with her friend everyday and with one eye she looks at my bedroom. Now, she is also coyping same type of clothes as i wear. She thinks im jealous, but i m not. Whenever, i sit in my balcony, she comes with her friend to play. I m getting irritated. What should i do? What should i say to her? If i say something, she pretends that the thing never happened and i m wrong. She is showing she is so good.