Help with a story im writing for my language arts cl?

So for our cl ignment we have to make and write a story and give it to the teacher by Wensday, and cause i like writing kinda dark stuff so first of all i drew a picture of the character i had in my head, then by the appearance i make up a story. I called her Ann, she's a 17 year old literate who's very quiet, and comes from a semi wealthy family, lives in Adelaide Australia, and she's deciding to try her hand at writing a book in which the main character a very innocent girl gets caught up in drugs and drinking and gets really on edge and goes from innocent to a bit on the mentally insane side, and as Ann is writing the book starts to become her life where she becomes like the main character. What do you think of this story idea, is it worthy of an A? Yes i did come up with this story on my own. But what do you think, any suggestions??