What to do about Mother in Law's upset about loss of independence?

Before my MIL went in the hospital 4 weeks ago, she was doing several things on her own, like getting a shower and staying by herself when I was gone from the house a few hours. Both of those things changed when she came home  from rehab 2 weeks ago and she is not taking the change well. She likes the aides we have hired as companions to talk to, but doesn’t want them to do any hands-on care. When the physical therapist reiterated last week that solo showers should be a thing of the past, she agreed. I was surprised and dismayed when she told me this evening, after I suggested she let the aide help her shower tomorrow, she said that was not necessary because she had gotten a shower herself this morning! We actually had a big row about it, with me insisting she was being unsafe (and stubborn) and her accusing me of being bossy and robbing her of her independence. She has Parkinson’s and arthritis and will be 93 next week.if I were an outsider I might say, good for her, at least she wants to do for herself. But as the responsible family caregiver, I emphasize “safety first” and find it really hard to just ok the solo shower. Neither of us backed down. Obviously it was a control issue with each of us believing we are right. Another issue that came up yesterday, she doesn’t want me mentioning any negative symptoms when she has her appt. with the neurologist next week. I think he should know what all has been going on, and I think she wants to put a false front on to make it look like everything is alright. She says I speak too much for her at doctor’s appts and maybe I do. Taking on this caregiving role too intensely maybe. Has anyone made any headway with similar issues?