I learned of feng shui almost 20 years ago. A lot of it makes good sense to me. Other parts seem like silly superstition. Keeping a good, clean environment to live in makes perfect sense. Having furniture and things arranged to be of benefit to you and not cause undue stress also makes great sense. Sometimes the orientation of a building and its location makes great sense too. Yet sometimes common sense dictates that some things just are silly. Every situation is different. Perhaps your bears some good thought and investigation with an open mind. You may find your sister is absolutely right. You may also find that your sickness has nothing to do much with your home. I would suggest finding a book about feng shui that focuses on the practical aspects of the philosophy and pays little attention to the superstitions attached to it. It is just too difficult to say one way or the other without knowing your home and seeing how you live, etc. for someone to give you a good answer one way or the other. Good luck and be well.