My dd is another example of a child who sailed through the "terrible twos" and then became unrecognizable at 3.5 years. A friend recommended Your Four-Year-Old: Wild and Wonderful by Louise Bates Ames. It's a whole series and it served me well when dd was six as well. Your Six-Year-Old: Loving and Defiant. (a perfect description). Adding all the OEs that gifted children may have helps understand the picture even better, but a basic understanding of what stage of development the child is undergoing helps too. The Ames series is old (late 1980's?) and it shows sometimes, but I found it incredibly normalizing and straightforward.
