How to approach an older co-worker about...?

I have this co-worker, she is a pain in the butt to everyone. She could probably be considered clinically O.C.D., and enforces this problem on everyone else. No matter how perfectly clean the building is, she and her husband (who do does not work here) will come in before everyone in the morning (she happens to have a key) and re-clean everything in the building. Then complain to the owner about what terrible people the rest of us are. The owner knows what she is like, and how she drives the rest of us nuts, but doesn't want to 'rock the boat'. If I approach the owner about it, she will ask me to take care of it. If I talk to said person about it, she gets very defensive, will tell the owner how upset this makes her and then the owner will just agree with her and not back me up at all. How else can I handle this? This person is 30yrs older than me. The reason this is a problem is because this is a massage clinic and her 'cleaning' includes stripping all the tables of their (already clean) pads, blankets, sheets, headrest covers. This is a total waste of resources, and time. Thoughts?