If she has dyspraxia, that is probably affecting her processing speed by both hampering her fine motor response (for things like Coding on the WISC) and also slowing down her recall. Also, in my research it says that dyspraxia and ADD are often comorbid in more than 50% of cases. It doesn't mean she has it, but that she may have symptoms of it.
Since she has dyspraxia and dyslexia, have you also looked at dyscalculia? The "dys" problems tend to come together.
My son has a 50+ point gap between his processing speed and everything else (on the WISC) and it is entirely DCD/dyspraxia. Three different experts have ruled out ADHD, though he looks similar because DCD makes him fidgety.
