Yes, the increase in verbal is fairly sizable, even with the Flynn effect. It probably reflects a number of factors at once. Some possibilities:
1. the day--at her age, she may have just been in a more testable frame of mind the second time around.
2. the structure of the test--the SB5 Verbal IQ includes measures of many other factors, including each of the five composite areas (fluid reasoning, visual spatial, quantitative reasoning, working memory, accumulated knowledge), versus the WPPSI, which has measures of verbal reasoning (similarities, comprehension) and knowledge (vocabulary, information, comprehension), usually based on one of each (similarities, information). Verbal IQ on the SB5 doesn't really mean purely verbal ability, but verbal ways of accessing various cognitive abilities. E.g., verbal visual spatial uses a lot of directional terms and spatial sense. Most people who are verbally capable, but have indifferent spatial skills, would do poorly on it, despite their strong verbal cognition. If I recall correctly, she did well on several of these other areas, either on the WPPSI or on achievement testing. This is probably one of the reasons the psych said it was good for IDing nonverbal giftedness--it just isn't as heavily weighted for pure verbal ability. Did she actually do significantly better on verbal fluid reasoning and verbal knowledge? Those would be the closest one-to-one comparisons with the WPPSI.
