Of course she is off book. She probably provides services equivalent to an CNA, with perhaps some errands or other casual assistance work tied in.

There's a big market for this sort of thing. Agency-based homecare is really expensive and usually pretty awful. Traditionally, these sorts of casual labor jobs had to be paired with a spouse's income to avoid IRS scrutiny, but IRS enforcement isn't what it once was due to years of funding neglect.

The notion that a bank is recognizing off-book income as income for lending purposes is incredible. Eventually the prospective lender will run into a problem, and usually will take an income hit when they are forced to land a normal job. The other turd about the "part time student" aspect is that she is probably living on student loans.