Pearson, the publisher of the WASI and WISC, has some information about the WASI on their
website. The part your daughter described as difficult is the block design subtest which is part of the performance IQ section on the WASI and the perceptual reasoning subtest on the WISC.
Essentially, the WASI is an abbreviated version of the WISC IQ test. I couldn't say why her verbal score came out as her lowest section, but someone here might be able to give some more useful input if the school would be willing to give you all of the scaled scores or percentiles for the tests that she took (vocab & similarities -- Verbal, matrix reasoning & block design -- Performance). The WISC adds another test into Verbal (comprehension) and another test into the perceptual reasoning/performance area (picture concepts). It also has two other subtests: processing speed and working memory. I suspect that the reason those two aren't included in the WASI is that they are less salient to intelligence than the capacity to show that intelligence in an academic setting.
