Old Duck being de-sensitized

This old mare that we keep alive (she doesn't belong to us) really struggles in winter, especially when it rains. She refuses to wear a horse blanket as it freaks her out, so my wife is applying her psychological training to solving Duck's problem. Yesterday she bought some fabric that is about the size of a saddle blanket and draped it on Duck. Duck has accepted this fabric now and is OK with it, so the next step is to gradually make the fabric pieces bigger and bigger until we get up to the size of a horse rug. Then we can put a real horse rug on her when the weather turns cold and she will survive the winter more comfortable. Clever, these psychologists.