it's not a bad story. the story line has a lot of potential. the problem is that you have too many tragic events one after the other (her parents having a divorce, her brother getting killed, etc) what you could do is write the story from the death of her brother and because of this her mother starts drinking which causes a divorce. and it seems to me you have a lot to say about the event so it may be a good starting point. either way i think this could very good if you change the order of the events. good luck :)