I rescue dogs just like you do. But it seems to me that you may be dealing with a common feeling I hear of a lot in the dog rescue circles. Unless you have the one dog that is going to cure cancer, you are having common feelings. Don't forget that, it’s a dog. Just because it’s a rescue animal it doesn't really know this. The dog also will not respond to reasoning like a human will, so you have to be careful that you’re not trying to "humanize" her to much. Because no matter how hard you try, it won't work. All that will happen is she will walk all over you and become unmanageable. Plus to add to it you have a Chow Chow mix, which is a bully breed like mine is. You need to be the alpha of the house and when you do; the rest will fall into place. I hope this helps.