One more thing that occurred to me, as I reread the OP and see the note about you needing a notebook to illustrate "simple concepts" - she may just be a strongly visual learner/communicator. As a not particularly un-bright but very visual person, I'm often completely lost when someone showers me with words, but give me a basic diagram and I have no problem with complicated concepts. Some people (like me) have a hard time organizing spoken words into concepts in their minds. At least, I'm assuming I'm not a freak in this. I think it's because I tend to unconsciously zone out and miss key words, and also have a hard time "holding on" to many sentences at a time, long enough for them all to come together.

Anyway, just throwing a potential non-type-related explanation out there.