Hopefully you read this...but my dog did the exact same thing. He was trained to go out and asked when he had to go, but then all of a sudden he started going to the bathroom inside. As well as zoe, he peed on my brother's bed and my parent's bed, and all over the house, including the stairs which was a hassel to clean. I'm pretty sure he was doing this for attention and that may be very well what your zoe is doing too, so I encourage you to check that out. I solved this problem by pretty much ignoring him. I keep him in the kitchen so what I did was put him down there and left him alone there for a while well we were all up stairs. I think he learned that when he did that he wasn't getting attention. *Remember that dogs also do things to get negative attention so sometimes the yelling doesn't work, we tried yelling "no" and so on, and my dog just continued going to the bathroom in the house. You can also try making zoe sit in a corner and stay there for a couple minutes. Hope this helps