I'm not familiar with the WPSSI so I can't help you specifically, but fwiw processing speed is often lower than VIQ and PRI on the WISC-IV - most of the time it doesn't mean anything, other times if the discrepancy is large enough it can be a sign of either learning disabilities or simply a bottleneck in processing speed that can frustrate an intellectually gifted child.
Were there any subtest scores included with the testing? If more than one subtest is used with the WPSSI to determine Processing Speed it might be helpful to see whether or not one particular subtest was lower than others - that in particular might point to a potential challenge. You might also want to look and see if there is any significant scatter among the other subtest scores (scatter being differences larger than 1 SD) - children who have learning disabilities etc often have a lot of scatter in subtest scores.
FWIW, my ds has a disability (developmental coordination disorder and an expressive language disorder) which impacts his ability to produce written expression and impacts his fine motor skills in a significant way, and he has a significant difference in his processing speed index vs VIQ and PRI on the WISC - but it's much larger than your dd's gap. I'd watch for the things ColinsMum mentioned, however - fwiw, we didn't discover our ds' disability until testing at the end of 2nd grade, after he'd become so upset at school that he was having panic attacks and overall was a very anxiety-filled child with clueless parents. Ironically he'd had ability testing when he was 5 as part of a school district gifted program entry requirement; that testing showed a similar gap in scores and the psych who did the testing didn't think anything of it at all other than to tell us that he was a "slowpoke with a pencil". In hindsight I wish we'd realized that the gap could be telling us something so that we could have understood that he was struggling at school those first few years and wasn't just a quirky bored gifted kid goofing off.
polarbear
