That's her ex-husband? That's impressive, they get along very well. Yeah, I don't see him as guiding anything either. If anything I think he asks pretty good clarifying questions about what she's experiencing. He elicits specific details (e.g. "Can you tell what he did for a living?" "How does he want to hurt people?") that lend credence to her 'abilities'. Any snake oil salesman can walk through an allegedly haunted place saying, "I think he's evil. I don't like it here. I think he wants to hurt people."** That guy puts forth handy nudges to be more specific.
As far as her type- INFJ wouldn't entirely surprise me. I'd be more inclined to think ENFJ if she's an NFJ, just because it seems like her default is to be really expressive (emphatic facial expressions and tone). I think generally INFJs are more controlled than that- we only become animated around people we've established a certain comfort level with. Although she's more subdued/calm in clips that I'd guess were shot afterward and inserted back into her 'walk' in order to clarify things, so I don't know. All I can estimate about her though is 'F'- pretty sure she's a Feeler.
Investigator guy: yeah, ISFJ is feasible to me too. I guess I'd say he smacks of ISJ more than of TJ, really. (And I'd lean more towards ISTJ than ISFJ.)
No idea about the ex-husband either, except he does have that ITP-flavored deadpan monotone. (TJs can be monotone too, but TPs react more to the immediate/direct environment.)
**Just once, I want her to do a walk through where the biggest problem is a ghost stealing marbles for the kids' board games or something, saying things like, "They're essentially harmless. They're playing Parcheesi. I like this place." My primary gripe with the show is that it's hard to believe- *if* there are really ghosts, that the majority of them are as malevolent as she describes. That, and the general production of the show is a little too sensationalistic for my tastes- with the dramatic music and camera shots and whatnot. Yet I still find myself watching a couple episodes every couple of days, so I'm clearly entertained enough to keep coming back.