I can completely understand how it feels to not being independent, and specially in old age when through out we have been self sufficient. As a family member I feel you need to understand this too, please be a support to her and getting her confidence back. You can involve her daily activities, she should feel valuable. This stress and anxiety is because of her inability to do things on her own. Spend time with her as a family, take her out for evening stroll, she can be seated in a wheel chair if can't walk much. She can be asked to spend some time on her, things which she likes, initially you will have to  engage her in them, she should not have time to think about her illness.

RA causes depression and her depression and anxiety also need to be addressed because that will lower her pain tolerance. she will need a lot of family support in addition to counseling.

Depression is very common with rheumatoid arthritis, if you treat her depression with agents like duloxetine her pain will also reduce and she will be much better , consult a psychiatrist