No, the landlord may NOT do this. While the landlord does have the right to show the house, on proper notice, for purposes of renting or selling it, YOU are the ones with the right to possession of the home (so long as you paying your rent, abiding by all lease terms, etc.). The landlord has no right to disturb that possession, including by moving your belongings. She is liable for any costs or losses you incur--even the cost of movers, if you hire anyone to help you move your furniture back--though be aware before voluntarily incurring costs, that if she refuses to pay, you'd have to sue her to recover the money. Moreover, if she does this again, you would likely have grounds to terminate your lease early without penalty if you chose, especially if you put her on written notice that this is unacceptable.If the landlord wants you to let her "stage" the house, the proper way to do that is to offer you some incentive to do so--e.g. she could offer to reduce your rent during the months she's trying to sell the home, if you'll let her stage it.