I think everybody who has ever owned a puppy can appreciate your efforts and commend you on adopting a puppy mill rescue. I know your efforts will pay off for both of you. I don't know if it will work for you but I feed mine 2 x a day and keep water down all day. They usually poop within a few minutes after I set the food down and they eat. Almost clockwork now. They are 11 months old now. I'm sure she will get in routine with you. Good luck!