
It certainly sounds like she is confused if she has been used to the dreaded puppy pads for house training, poor girl.
I would and have done what others have advised in your situation. Keep her with you and watch her like a hawk at all times so that she doesn't get the chance to toilet in other areas of the house. I always feel that if they do this then it is almost like they become used to it and think that it is ok.
I still have the odd accident from my 5 month old and that is normally because I have not been watching him as closely as I should. We had a regression a few weeks back and he was messing in the kitchen almost daily. I went back to basics with him which meant taking him out after meals, sleep and play. I also find that if I stick to a rigid routine of feeding times, then I know when he will do his business and take him out specifically at that time. I find that routine normally helps them greatly and also I use a crate for the times that I can't watch him or I go out, as he doesn't like to mess in the crate.
I too was up during the night several times taking my boy out up until a few weeks ago and then I cut it back to once a night and this may explain why he was messing sometimes during the day...I don't know, just wish we could speak dog sometimes. lol.
It is a very positive step that she is starting to go to the toilet on walks, as Jodi has said, maybe now that she is doing this, the light may have switched itself on. I hope so for you and her.