Overall, she does have scores that suggest Average ability, both cognitively and academically. I would not describe her WIAT-III as overachievement, but as consistent with her verbal cognition, which is Average, approaching High Average (verbal reasoning is High Average (equivalent to 110s), so we could reasonably suggest that this is the optimal estimate of her cognition, validating your sense that she presents as higher than the FSIQ obtained). (BTW, I assume that spelling score is actually 109, and not 10.) She does present with personal weaknesses in visual spatial and fluid reasoning domains, and likely with specific aspects of working memory, all of which appear to be best estimated in the Low Average range. If there are vision or visual processing issues, these scores may change at some point in the future, with effective intervention. To be fair, though, my experience with the FR subtests is that vision doesn't affect them quite as much as it does the VS subtests. What I do find associated with lower FR is the rigidity, quirkiness, sensitivities, and sometimes challenging behavior that you are reporting; this may be conceptualized in the context of nonverbal learning disabilities.
WRT Picture Span, I should note first that hitting the ceiling in age-equivalents is not the same as hitting the ceiling of the subtest, especially at this age, which is roughly in the middle of the age span of the test. Actually, before that, I should note that age- and grade-equivalents are not a recommended measure for interpreting this instrument (or most psychoeducational/neuropsychological instruments, really). The scaled and standard scores are what the instrument is designed to interpret. This scaled score is properly considered the Very High (not quite GT) range. Secondly, there are several key differences between DS and PS, any one of which could result in this kind of split. DS is auditory, and PS is visual. DS is symbolic, while PS uses concrete-meaningful images. DS includes three conditions: forward, backward, and in sequence. PS has only the forward condition. I can speculate on several possible reasons for the difference on this data set, including: perhaps your DC does better with remembering meaningful information than random symbols; her rote memory (forward) may be much stronger than her manipulation/working memory (backward and sequencing); she may have better visual memory than auditory memory (despite verbal performance stronger than visual spatial thinking). Without additional context, I can't tell you which of these is most likely.
As to her teacher's reports: her decoding skills would place her in the top reading group in most average-sized classrooms, but her comprehension skills are quite consistent with average verbal cognition. This lines up well with being in the top of her class, but not standing out as exceptional. The challenging behavior very well could be related to the disparity between Average to High Average verbal cognition and Low Average visual performance (whether for perceptual or visual reasons). Numerical Operations is in the low end of the Average range, which would not place her in the top end of the class in a typical classroom, but in a middle to lower group. This may be related to the relative weaknesses in working memory, which is an important contributor to accurate math computations. On the other hand, her math applications/word problems are solidly Average, which is probably keeping her afloat in math. I'm not surprised art makes her angry, given her profile of visual relative weakness. At some point in the next few years, as math changes from arithmetic to abstract problem solving, she may begin to find math increasingly frustrating as well, especially if her fact fluency (not assessed/reported here) is lower than her computational skills. I'm guessing she's in fourth grade, which is often about when that transition begins. This may also be feeding her current difficult school experience.
Although her current data do not necessarily indicate a learning disability, I would keep a close eye on her math achievement moving forward, as well as her coping skills for frustration tolerance and social perception, as these are all risk areas associated with lowered visual-perceptual and nonverbal fluid reasoning skills.
