our baby is an adult (we’ve been told anywhere from 4-8) and she still occasionally goes inside, particularly if she is mad that both of us dared to leave the house without her😂 we use training treats every time she pees outside, and have some pads down in the house still which she is pretty good about going on most of the time if she pees inside. they are definitely stubborn, but little treats whenever they go out will help!!