couple things came to mind reading your post.
--does she have issues with motor skills or look klutzy? If so, look at developmental coordination disorder on Wikipedia. Those with DCD often have working memory issues (the kind where you are disorganized and have problems with steps or sequences). The reason I ask is because you said her handwriting is a mess (which is common with ADHD, I think, but something like half of people with ADHD also have DCD).
--DD has ADHD and they are working on this stuff (executive functioning ability) in occupational therapy. If her writing is poor you could look at OT for that as well. Sounds like you are working with a psych and I'm not sure what the pros and cons are of going w/ a psych vs. an OT
--in terms of meds, DS's first grade teacher mentioned that she thinks he has ADHD--inattentive type. He looks very spacey at school (but he is the opposite and DOES NOT like writing, and half of what they do there involves writing. So it's hard for me to figure out if it's really ADHD, or executive functioning issues due to his DCD, or a learning disability like dysgraphia). I know how much meds help my other kid so we did a trial of ritalin (a low dose) with DS and the teacher said that it looked like a huge difference in the few days she was able to observe. It might be worth it to talk to the doctor about doing a trial, and see how much of a difference there is, and if there is a big difference, whether it's worth it to deal with the possible side effects. I didn't notice any side effects with DS, at least on that low dose.
How did she do with processing speed on the WISC? Coding was the lowest score with both of my kids on the WISC. DD actually has a good working memory on the WISC (at least when medicated)...it's in the 96th percentile. DS had a huge gap between perceptual reasoning in the 140's and everything else in the 110-120 range.
