Speaking as someone who normally likes kids, Kii is really annoying.
As someone who is around a great many kids, I can't quite understand your comment. As a child-like youkai, she is somewhat selfish, but far less so than several children in my family. In several of the chapters, she wishes to share (the Christmas cake) or help and be appreciated (OK, that one could be construed as selfish, but I really wish some of the children I'm around would be selfish in that manner). I, too, like children, but (I'm not a parent myself, merely an uncle) I find that there are an awful lot of incredibly spoiled brats out there these days. If Kii is the epitome of spoiled children, I wish that a whole bunch of the children in Southern California would copy her example, and they would be far more pleasant to be around than they are now.