OHSU and Child # 2

I just love signing my kids up for studies. Am I sick? Is there a little Munchausan by proxy issue? Do I view my brood like bacteria in a petri dish?
Actually, I am prone to saying "oh Hell, why not". Here we have two kids, brother and sister, both on the spectrum, with similar issues translated differently due to what? Gender differences? Personality differences?
Olivia just started the OHSU Communication Study at the Beaverton Campus. 8 sessions, each evaluating how she communicates and how she absorbs what others are trying to communicate. Isaac participated in this study in the Spring and it was a good experience, and at the end we had a priceless piece of paper in our hands - an intense evaluation of how Isaac thinks and learns, 20 pages long. We applied it to his IEP, with great results so far.
So it is her turn. So far they have tested her hearing and vision, to confirm that these are not limiting her communication. Now they have started on her cognitive skills. This step raises the Kracken of Worries for me - what kind of playing field do we have, what basic tools are we working with? Although I know better, that evil statistic I read 4 years ago still lurks beneath the surface "70% of children diagnosed Autistic show signs of Mental Retardation". How much (if at all) is O affected by this? What are our limitations?
Of course, if OHSU finds that there are signs, I will ignore them anyway. I am good at that. I will assume she is typical (just as I do with both kids now), just taking a different route. But still...nope. This study will let me know in what way she takes in information best. And I will use that information to tackle her upcoming IEP this spring (holy shit, am not ready to go from IFSP to IEP yet with her).