DS and DD read 3rd or 4th grade level book before entering K. They hardly spelled any word at that time. One reason could be I had never taught them phonics system in US because I had never learned that. They just remembered the words and didn't pay attention how to spell them. DS picked up spelling quickly after few months in K. Recently he scored 99.6th in WJ-III spelling subtest but he only scored high average in verbal of WISC. DD6 is gradually improving spelling skills while writing journal everyday in school. Ren, I remember your DD is in my DD's age so don't worry about that. In my son's case, verbal ability on IQ test dose not reflect his spelling ability. When your DD learned how to learn spelling efficiently, she could improve in flying speed.
