My MIL adopted this toy dog from the shelter a couple months ago. She was not potty trained and a 1 year old. Shelter told her this was the dogs 3rd home. She is about ready to get rid of the dog. The dog is pretty much perfect in every other way, but she's wracking havoc with peeing and pooping all over the house. MIL takes her out every 2 hours religiously and when she shows signs that she might have to go (sniffing around on the carpet). She rewards her when she goes potty with a treat. How do you potty train a dog that has obviously been used being able to pee/pooh in the house?