A steadier ground guide to the stretch when she can still turn help away, and sometimes shouldn't. What's really behind the refusal, what to say, and when a no needs more than patience.
Notice what her "I'm fine" sets off in you, whether it's hurt at being shut out or the cold fact that you'll be the one cleaning up whatever goes wrong. Both are fair, and neither one has to be the voice that makes the next offer.
Before anything else, ask whether this is new. A woman who has turned down help her whole life is showing you her character, and a woman who took help easily a year ago and now pulls away is showing you a change worth explaining. Depression is one of the likeliest explanations. It's common in the early stage, easy to miss under a dementia diagnosis, and often shows up as irritability, withdrawal, and flat refusals rather than obvious sadness. Pain she isn't mentioning, poor sleep, and a recent medication change belong on the same list, and so does an infection when the change came on over days.
Once the body is checked, listen for which kind of refusal this is, because the two need opposite handling.
What decides how hard to push isn't whether she's right about needing help. It's what happens if she's wrong for another week. A checkbook balanced late, a kitchen cleaned imperfectly, dinners simpler than they used to be, these cost little to leave in her hands, and backing off protects trust you'll need later. Pills skipped or doubled, a burner left on, a bill heading toward a shutoff notice, these carry a cost someone will pay, and they're where you keep offering in new forms and bring her doctor in if nothing changes. When every refusal gets treated as an emergency, she learns to refuse all of it, including the few that matter.
When the same offer keeps getting the same no, change the offer rather than the volume.
For three days, note each offer she turned down, the task it involved, and the hour, along with anything she did accept. Refusals that cluster on one task point to what that task means to her, and refusals that cluster late in the day often point to fatigue more than to the help itself.
Print the one-page log if you want somewhere to keep this, and take it to the appointment.
This is what the tracking is for. Dates, times and specifics turn "something's off" into something a clinician can act on in a ten-minute appointment.
Every task she keeps is a piece of herself she gets to hold a little longer, and letting her keep the safe ones is part of how you protect her from the dangerous ones.