I stay with my Mom more than 14 hours a day in her home due to dementia. She has a medicaid aide while I am at work. Her only income is medicare at less than 900/month. She refuses to move to my home and is unsafe to live alone. I provide her care and any additional finances although I have not actually kept track of the money spent. I work + have my own home.
Eventually you Mom would need to apply to Medicaid as she will need 24 hour care, and it is physically impossible for you to do the work of 3 full-time Caregivers each day. With Medicaid, that program can help pay for her care in a nursing home. I know you said that she refuses to move, but it will come a time where she no longer has a vote when it comes to her safety and care.