I admitted that a while ago. My question (see post 1) was medical, not looking for help handling geriatrics.
But Ted, if you can't get her to a doctor, then all the medical suggestions in the world aren't worth an inflated plug nickel. The best suggestion you've had so far is to make sure she gets a tilt-table test. But how to do that if she won't go to the doctor? In the end, it does come down to how to induce your Mom to do what is best for her, and that's the hardest question of all.
My dad wouldn't go in for chest pain. He had a script for nitro, and preferred to try that and wait for the pain to pass. Of course it did every time -- until it didn't, and he didn't reach out until it was too late. And he was mentally very competent -- physically too, until he wasn't. Fortunately, he was 93.
My mom was a much sadder story. She fell multiple times in their home, at first minor falls, and then she fractured a hip rolling out of bed trying to reach for something on the nightstand. After that she was disabled for the rest of her life, but kept trying to walk unassisted and fell many times after that as well. She was in and out of hospitals and nursing homes for 3 years before the end. She was 91, but so what? My dad had power of attorney and lived with her, but there was nothing he could do to prevent her living through that horrible existence. The only way to prevent it would have been a permanent nursing home (which we didn't have the heart for) or 24/7 home nursing care (which she adamantly refused).
As long as your mom is legally competent there is really nothing you can do short of an "intervention", which probably won't work without more family members to confront whatever counter-arguments she brings up. You didn't say anything about cousins? Your mom's siblings (if any)?
Can she afford 24/7 care at home? A close friend arranged that for her mom for her last years, but there is no way she could have afforded that except that her injuries were caused partly by an auto accident, and insurance paid for every penny of the care. Sometimes the worst circumstances lead to the best (possible) outcome. But sometimes they don't.