Since it took me so long to get my little girl trained, I really have no room to talk but, I will tell you what finally worked for me. The first thing that really did the trick, and probably would have worked even faster had I done this from the beginning, was to make dedicated bathroom runs that if unsuccessful would lead to more kennel time. So she's out and playing and it's time to take her for her "business" trip and we leash up and go outside. Maybe it's raining or maybe it's too cold or maybe something gets her distracted so she doesn't go to the bathroom, after giving her a reasonable time I bring her back into the house and straight to the kennel. She gets 15 or 20 minutes of kennel time and then we go right back outside so she can relieve herself. If she does, then we get some free time, if not, it's right back to the kennel for another 15 or 20 minute wait. Just kept on repeating this over and over until she got the idea of what she was supposed to do. Now, it doesn't matter if she's inside or in her outside run, the first thing she wants to do when she gets her leash on is to run outside and go to the bathroom. It's the coolest thing I've ever seen for taking a dog to the bathroom. It doesn't matter if it's cold or wet or anything, she is up for the job the instant she gets her leash on.
Now as well as this worked for her, and it work very well, there were two things I also had to learn with her. The first was that she was still like a little child and cannot be left alone without supervision. Whether I missed the subtle clues she would give or if she never even gave them, I found that ignoring her while she was loose would set us back a bit in our training. The other thing that I found was that I had to learn not to raise my voice. I come from a loud family I guess, perhaps from working around machinery too many years or something. It didn't have to be when I was scolding her, although that never worked out well for me, but if I spoke too loudly at my wife or my granddaughter I would likely find a nice little present hidden from my immediate sight. I eventually learned that I could live a happier life if I kept my voice a little softer, especially when I was correcting her. And it seemed that the softer I spoke, the faster she would respond to me anyway.
Like I said, I really have no business in giving advice on this, but I wanted to share with you what I found that worked for me. Best wishes and I hope you find what works well for you.