Can my landlord come into my house and show my house anytime she wants, without any written notice? I live in Missouri and my landlord is always walking into my house when I am gone... We are moving out and gave proper notice. She is demanding we have it clean 2 weeks before our final date that we are paid through, so she can show it, and we found her wandering around in the house the other day.

Read your lease. Generally this is specified in the lease. But the law generally allows a landlord to enter only with reasonable notice.

Notice does not always have to be in writing and often only has to be 24 hour. That can include telephone calls and the such, even a note posted on your door.

... She is demanding we have it clean 2 weeks before our final date that we are paid through, so she can show it, and we found her wandering around in the house the other day.

Send her a letter formally demanding that she cease and desist from entering the premises, in the absence of an emergency, without prior notice of the date and time she intends to enter. And, while you are at it, tell her that she can expect the premises cleaned by the time you surrender possession to her; not one second sooner.

If she continues to enter without notice, report her to the police as a trespasseer.