It doesn't mean she isn't disciplined, only that in this aspect she still needs to be scolded and taught. But all some of us are saying is that we don't see Sunghoon doing that. He let's her win. That isn't teaching her. I think she is four, which is a crucial age for her to start learning these life lessons. She might not understand fully, but it is important to reinforce habits. Of course it won't be perfect, but it is a start.