Reverse everything in the house.
Her bedroom drawers for yours, top to bottom. Socks and underware in botom draw, all the shit from the bottom draw in the top. Plus reverse yours for hers etc.
Kitchen. reverse everything..... Instead of Knives, forks, spoons. Have spoons forks knives.
Put everything in the complete opposite place that it started life.
REVERSE EVERYTHING IN THE HOUSE!!!!
Go on. Don't ask why. Just do it!
Make her think she's living in a parallel universe.