My room mate(20 yr old girl) is MESSY.?

Who's name is on the lease? If it's both, you really can't boot her out. If your name is on the lease you have the option of kicking her out. I think you need to sit down with her and firmly tell her that your both sharing the house, and both of you are responsible for doing the chores equally. Sit down with her and come up with a list of chores that you will both do, let her know your not pleased with her cleaning habits. Let her know if she acts up again, you will report her to the landlord. Most places have a lists of rights/responsibilities, and I would think if she continues to keep the place as a health hazard, then the landlord will evict her.