Within those constraints, what can I reasonably say about...
- her “academic” knowledge (reading or pre-reading, math, science,...)
- what kinds of things she could and could not do in her off-the-job life (cooking, other housework, shopping, using a telephone, games...)
- what issues, if any, may be subject to a formal behavior-management plan
- what tools or other accommodations she might use
Basically I want to avoid the trap of “I know how five-year-olds of normal intelligence behave, so I’ll just portray someone like that in a forty-five-year-old body”.
I talked with a friend of mine about what her sister with microcephaly can and can’t do (e.g., she can recognize logos on cereal boxes and such, but can’t recognize words in an arbitrary typeface), but since this sister does require one-on-one supervision, my character might be functioning on a somewhat higher level. I also did some poking around the Web site of the Massachusetts Department of Developmental Services (formerly the Department of Mental Retardation) and googled phrases like “moderate intellectual disability”, but everything I found discussed the issues in too-general terms for my needs.