Agreed. But I would argue one way to start typing them would be their interpersonal skills, being very conscientious of what they're saying and how it comes across (more your Fe side) and being attune to the situation at hand and consequently adjusting to make themselves fit in more as well as making those around them more at ease, and then just the sense that they're holding a lot back, and there's a lot more that's not being said. That could be a start.INFJ's are complex, and hard to get to know. Their behavior can look quite different from one INFJ to the next. That is why they are so hard to type.
I wish I knew some high IQ ISFJ's so I'd have a better comparison!!! I only know a couple of high IQ ENFP's, an ENTJ, one of my INFJ friends, and then myself. And yes, all, even the ENFP's, definitely feel disassociated on some level from people in general. But anyway - I haven't seen anything in Michelle's behavior that disqualifies her from INFJ. Now it doesn't mean she is, but I haven't seen anything notably anti-INFJ, just using my friends and myself in comparison - except perhaps the smoking thing. :-PAny person who has a significantly high IQ is going to feel this way as well. The high IQ makes them feel different than everyone else. If the person is also an introvert then that is going to make them feel even more misunderstood and disassociated from people in general. It is quite common for high IQ IS's to feel this way.
Oh, and her quotes where she mentions 'crying hysterically at the end of the day', being overloaded and not being able to sleep, and being easily influenced and affected by other peoples' opinions seem more F to me.