Unless you have strong evidence that she is dementing, and given that persuasion has failed so far, there is nothing you can do. She is legally entitled to decide what she can and cannot do and the Mental Capacity Act is clear that we cannot protect people from unwise decisions or behaviour UNLESS they are mentally 'incompetent' (in legal terms). Sadly, therefore, you cannot protect her from herself, and in her terms, it's served her well so far! Circumstances will intervene, no doubt, at her age. She might well have a fall or a medical event, but she knows that, and is prepared to take the risk. Very old people tend to view these risks differently to younger people. It is you who are suffering, but if appeals to her fail, you have little choice but to live with the uncertainty. There is an American Occupational Therapist called Teepa Snow who has written and lectured widely about 'elder' matters, principally dementia, and she characterises the elder fiercely independent person as a 'diamond' - glittering and apparently hard on the surface and reflecting all your emotional insecurities back to you! It is difficult, but you are doing your best. Good luck with your mum.