Hi Southlake,
I can't offer up the same level of professional advice that aeh can (and once again, aeh - it is such a blessing to have you hear helping us!) - but I can offer up a quick parental observation
My ds has a similar difference in VCI vs PSI, and although he's not had the WIAT he has a similar pattern of low scores in fluency measures on the WJ-III Achievement tests. FWIW, it might help to look at the subtest scores on your dd's PSI - were they even or was there a difference? The dip in scores on processing speed might potentially be related to either a visual challenge (eyes not tracking together well etc) or a fine motor challenge. There is a subtest under PRI which is also potentially impacted by either of these issues (sorry I can't remember which one at the moment!) - which might be why your dd's PRI is low relative to her VCI.
Many of us who've had children with this type of pattern had a follow-up test of visual-motor integration (Beery VMI) - which will sort out whether or not it's a vision issue or a fine motor issue (or neither!). It could be as simple as she writes "slowly".
Did you have your dd tested for a gifted program, for curiosity, or for a different reason? Just curious if there was anything going on with her academics that prompted testing and that might help explain the scores.
Best wishes,
polarbear
