Molly has big time regressed with her potty training

She did soooo good at first. It was like it only took a few days and she was peeing and pooping on her pads 98% of the time. I should have known it was too good to be true and that I should have kept my big mouth shut instead of bragging on her like I did. Now, she may pee on it 50% of the time, maybe, and poops everywhere EXCEPT on her pee pee pads. I give her treats everytime she does go on them and I try to put her on her pad when I catch her going somewhere else, but most of the time I find it after the fact. Once, I put some poop on the pad for a little bit so she could see it there, but I couldn't stand that, plus I figured that wasn't going to work anyway.
At night or when we are not at home, she stays in a playpen. She has a small bed that she sleeps in, a small water/food bowl and a pee pad. She does use it 95% of the time. But what am I going to do about the rest of my house? There is no way I can gate of portions of it because I have large doorways like into my den and kitchen and living rooms and stuff. Plus, it would lock out my three year old! HELP!