Working memory: the WISC-V includes measures of both auditory working memory and visual working memory (sort of--for some kids it is the visual component that is important, for others it is the concrete nature of the images, which allows them to put a meaningful name to the items they are remembering, versus meaningless numbers). The WISC-IV had only auditory working memory using semi-random symbols.
Paper vs digital: most of the digital format is the same as the paper and pencil, as the actual paper part (coding and symbol search) is still being administered on paper, and the remainder of it is either purely oral (nearly every item of the VCI, except at the very lowest ages), or just presenting the stimulus book items on an iPad screen instead of a flip book. The blocks are still real blocks, and you still respond to the stimulus book by pointing or naming your response. The differences are mainly on the examiner side of the easel. While it is possible that some children with ADHD will find the iPad more engaging, my experience is that children with ADHD are most affected by how engaging the examiner is, not so much the materials. This includes the affect, social skills, and pacing of the examiner.
Flynn effect: some examiners are finding the WISC-V scores noticeably lower than the WISC-IV, others are finding them higher, and still others find them to be comparable. The validation studies did not find unusual score depression, beyond that expected from the Flynn effect (about 3 points per decade for those near the mean, somewhat more for those to the right hand end of the curve, and somewhat less for those in the left hand end of the curve). I like it better for 2e children, as I think the factor structure is better at calling out their strengths.
Adoption/estimated age: Age brackets are generally in four month increments. By the time children reach WISC age, I would not think that a difference of a few months between "real" and test age would make much of a functional difference. Early deprivation does affect intellect. But so do many other things, not all of which are very well defined, nor are they under our control. I prefer to think that this is water under the bridge. Focus instead on how much better off she is in every way, intellect included, because you have loved and cared for her.
