I would like to say that I loved your thread title!! That's really it, isn't it?
Mine have it a bit easier as they are both outdoor and pad trained. So they go on their own inside but always come and tell us afterward to get their treat. I don't know if Reggie's missed a potty treat in 11 years.
Sounds like you're doing GREAT. Here's something else to maybe try: Since you are using the leash to take her out, start weaning her a little by dropping the leash while saying "Gotta Go Potty?" or something. Let her start going to the door by herself. And if you start getting her "excited" during the walk to the door, you might train a certain recognizable behavior. Then you can drop the leash until it's time to go outside. She'll be telling you to go get the leash!
My older Reggie goes to the stairway and gives me the "look". I ask "Do you need to go potty?" and he goes crazy, whirling in circles, and jumping. I take that as a yes.
Then he waits. I say either "Outside" (nice day) or "Downstairs" (pouring down rain) and he takes off in whatever direction I say. Coby will get their eventually. And so will you!
Great work so far tho.