Lies and the I Dont Knows

Up until recently I had a daughter that was really sweet and would do things for you. Now she cant remember to finish her work in class of to even bring it home to finish. She has begun lying to us about it. We had a conferance with her teachers and she pretty much said that they were all lying to get her into trouble. Just this morning she supposedly took a shower for 3 minutes. She was walking around the kitchen with a towel on her head to cover "wet hair" I pulled the towell off and her hair was bone dry. As i was taking the towell off she said, I dont know how my hair got so dry that fast. UUUUUHM you didnt wash it. So that's another lie. Oh and she knows it all too. If I could go back to my teen years and change things I would. I would change to fact that I never listened to anyone about anything. I would be a much better balanced, well educated individul now. I guess you learn from your mistakes, but how many people have died getting there. Im fed up I dont know what to do. We are getting her to see a Dr. soon maybe that will help.