We had the same problem with Lara, it did take a while, so I do symapthise. It was the one area I made no progress on for quite a while, and was demented

Lara would be outside and do a poo, then come back in and pee in the house. Even now, she doesn't have any real signals, so we stuck to the startegy of regular outside trips, treats for success and dancing about like a loony, that seemed to please her more

I am still in the habit of popping her out on a regualr basis and I think that is just how it will be. Hang in there, I know it's easy to say, but you will get there.
