DD is four and three-quarters and in general is a very sweet, intelligent and good child. BUT over the last few weeks she has had phases of being incredibly difficult, in that she will just not listen. If I try to discipline her by telling her in a "bossy" voice that she is being naughty, she treats is like a joke and tells me that I am being rude to her. If I take it further, by using a harsher voice, etc. she will start crying. Is this just a phase?