My mother has dementia, alzheimers, diabetes, arthritis, neuropathy and heart disease. I take care of her full time. Getting help for the bath tub would give her some independence back. I have to help her put her legs in the tub. I stand by her in case she gets unstable and she doesn't mind but always says she wants to be independent.
It appeared my relatives would need a whole bathroom remodel but the OT had great solutions that could be done quickly for much lower cost.
There can be compromises too. Eg a basin & flannel wash while seated in the bathroom could be done independently - while a shower/wash with handheld hose could be with your assistance. Could alternate days.
Even just a simple thing like having a chair to sit on while drying & dressing can improve safety. (eg slips / trips on pant legs).
From the ailments you mentioned, I would be thinking high falls risk due to any one of them: stiffness (arthritis), lack of sensation (nephropathy) fatigue (heart disease) & most importantly, possible lack of insight (dementia). The sum together = very high Falls risk (my opinion only based on words, not seeing your Mother obviously).
Sometimes an elder is happier to change routine if "that nice OT man/lady said I should do it this way now" 😉
https://www.homedepot.com/p/Cleancut-Wide-White-Convertible-Bathtub-Conversion-Kit-C-W-W/305048651
She would also need grab bars and a shower chair. Also very helpful would be a lower shower head with a hose/head attachment that she can control.
If your mother has dementia and neuropathy and is unsteady on her feet, she doesn't "get" to be pretend to be independent. The fact is she's not (because you're helping her) and she will need more and more help. Just because someone lives in their own home (aging in place) doesn't mean they're independent if their helpers are orbiting around them in order to keep them there. You may find this to become an unsustainable arrangement. Just food for thought as it will be very expense and time-consuming to adapt her home to her coming needs.