Great advice and great encouragement already above. So I'll just elaborate on the carpet cleaning. We have an elderly cat that developed the habit of going on the carpet. I can tell you if you think you're cleaning it by just spraying a little of nature's miracle or similar solution on there and blotting it up, you're very wrong. You have to reeeaaallly read the directions and get serious about cleaning the carpet unless you want to get new. You have to literally DOUSE the carpets with the stuff and then cover it with wet towels to give the little enzymes the time to eat all the waste. Oxygen simply kills the enzymes before it's done. So we had to do that in one area (thank goodness!) of our carpet for several days before we got it all. Still, to this day, the animals "pause" there, so I'm still not sure we got it all. You say that she goes on a new spot, so either she really has gone there before and you don't know it, or she really has trained herself to go on carpet.
And, in your end-of-the-rope frustration, I also agree with just going the "panty" route. I had a female that had submissive urination that we had to do that with.
Good Luck!!