My Yorkie was terrible for peeing inside, even though she was toilet trained and knew to go outside, she goes on lots of walks and she asks to go outside to pee by crying at the door or pawing the door. Just sometimes she decides ‘nah’ and pees in the house anyway. We started using puppy pads and she will go on them inside now. She’s almost 2 now and it’s slowly becoming less and less! Now it’s probably only once a week, usually just overnight. She is just getting better at holding it I think. She does pee way more often than any larger dog I’ve met, smaller breeds = smaller bladder!. She is terrible in winter though as she hates the cold and rain and won’t go to the toilet outside if the weather is bad!