What would you do if you were me?

I am 18 and I have a friend, Mel, who is 17. We've known each other for a while and have always been rather close. I am a gay man and she is a straight female. She, however, seems to obey to everything I say and copies the things I do and like. For example, both of us were quite fond of Amy Winehouse for a while, and I said, ''How marvelous this woman is with her rock n' roll attitude and in-your-face way of living!'' Shortly after, Mel had begun skipping school, having with random men at parties, and engaged in debauchery. Soon after, I became quite fond of Blair Waldorf, who is a character in the show Gossip Girl. I said, ''How elegant this woman is with her strict school views, wanting to go to Yale, and beautiful style.'' Mel then started dressing in a more preppy way, like Ms Waldorf and began studying and attending school all the time. I thought it was rather lovely to see, but she now studies up to 5 hours a day, until she is exhausted. I also suffer from OCD and she pretends that she's going to the mall to purchase cleaning products when, in fact, she's at another friend's house, probably talking about me. Why does this woman look up to me so much?