Worried about my mother

I am extremely worried about my ageing mothers welfare and am having trouble deciding how to move forward. My mother is in her 70s, has memory problem that are currently being assessed for dementia. She has physical mobility issues and suffers dizziness and unexpected falls. She has had various members of our family stay with her and care for her at t8mes, with the current family member (a young man) having been there for 5 years. He spends all his time in his room playing computer games, and doesn’t socialise with her. He doesn’t take her out or assist her around the house. She relies on me coming to visit to take her out and run errands. This young man has also been chewing through her bank account at a fast rate. My mother always says that he asked for a loan and will pay her back, it I see no record of him paying her back. She has signed power of attourney over to me and my family are pushing me to forcibly move her into my home. I don’t really want to upset her by forcing her to move and am not sure what to do next. Has anyone had experience like this?