There could indeed be an undiagnosed or undisclosed problem, either a disability or a major life event, or unpreparedness for college, plain and simple. I believe I have been very open and inviting to have a come-to-Jesus talk, but that it is beyond my station to force it on the student or to suggest counseling, either of an academic or psychiatric nature. Furthermore, I am NTT; I shouldn't even be giving a darn. (I say that ruefully.) The thing that gets under my skin is, this is not an actively problematic student. Not giving me any flak. Not being actively anything. As Arty_ says, just incurious -- about EVERYTHING.
Regarding the curriculum: some of the courses are the established department courses with established methods of evaluation with established grading scale. A clinically deceased person could potentially pass some of those courses. Another was writing-based, with some group projects, collectively graded. On participation the student has never received above a C- (indeed, last time was a D-, after which she wrote me and I clarified why, and she has never tried to improve). That's how these types of students get passed through, in our department. It's a major problem. There is not a benchmark that students must surmount before graduating; the department faculty had a discussion about that very thing and, uh, some of us decided against it.
She sounds very like Egilson's student. She says she "loves" our subject. I suspect that she loves having found a major in which she can essentially do no work, make no progress, and just clock in.