My foster dog had one accident in the middle of the night, both pee and poop - after weeks of solidifying her training to go on an astroturf mat on deck (I live on a boat). First thing I did was thoroughly clean the floor and eliminate/neutralize urine odor with vinegar (it was a hardwood floor). Then I started feeding her in that spot and confining her space at night when I wasn't able to watch her. I gradually gave her more space to roam around the cabin at night. She hasn't had an accident since. I'm guessing you don't want to feed her on your duvet, but maybe you could on the rug? Dogs don't like to mess where they eat and sleep, if they can help it.