MorningStar, your current state of confusion is quite understandable, but also exactly the reason that going ahead with an evaluation may give you all some more peace of mind. At the moment, you have a lot of questions and ambiguity, but you also know two things: 1), your DC feels there is a problem; and 2), no one really knows what it is. The purpose of the evaluation is to assure your DC that her concerns are taken seriously (as you note), and to try to bring clarity to what "it" is (and thus to help guide any helpful responses).
As a parent myself, I know that quite often we feel that we should be able to identify and solve our children's problems, so I totally understand the frustration of not even being able to pinpoint -if- there is an observable problem, let alone what it is. But it may be that this is something that is evident only internally, and, in any case, this is why you are hiring a professional. If it were something you could easily figure out yourself, you would have already done so!
