What to do?

It seems these 90yr olds so well until an accident. Its a shock to their system. And going under can cause some "fog" until the anethesia wears off and in the elderly that can take a while.

Maybe ur wife is going to need to help her. She only needs a good shower 2 or 3x a week. A sponge bath will do in between. With a broken wrist she may need some help dressing. Do not take her food to her. If you sit down for meals, she needs to too. I fed Mom breakfast and lunch in her sitting room because we eat haphazardly. But dinner was always at the diningroom table. Don't disable her.

I agree about the shower chair and a handheld shower head would be good. Bars...until u can get permanent ones there are those with suction cups.

Is this a big change from before the accident? Have you talked to her about it and what does she tell you? Does she feel helpless with one hand out of commission or is she having pain. Often in hospital in repairing these things they give some anesthesia? Did she have a general anesthesia at all? Did she have an indwelling catheter while in hospital? She could have a UTI and a simple dipstick over the counter test might help eliminate that.
I am hoping this is just a temporary change for her, but at this age you can't know. Discuss it with her and with the doctor if it continues. Sure wish you the best of luck.

Pjmax1, do you think your Mom [or is this your mother-in-law?] would be happier living in senior living? She would be around people closer to her age, and she could develop new friendships. Such places have activities for their residents. Would such a living arrangement be within her budget?

My Dad had moved into senior living and he really loved the place. He had wished he would have moved in years earlier, but he never knew such places existed. He really enjoyed the restaurant style menu dining.

I found a question you had asked several years ago https://www.agingcare.com/questions/mil-moved-in-several-years-ago-she-helps-very-little-and-i-feel-like-she-wants-to-be-waited-on-453997.htm Is this the same person?

What does her doctor say? Can you move her to an assisted living facility? The lack of hygiene might indicate dementia.

Get a medical opinion asap. Sometimes these "little" things can bring on depression. Good luck!

What safety measures do you now have.
There is a very good possibility that she is scared that she will fall again.
A shower bench or chair would minimize the chance of her falling.
Good sturdy grab bars where they are needed. (replacing towel bars with grab bars is a good start, towel bars are not intended to be used for support but that is what happens often)
Removing any trip hazards throw rugs, extension cords, excess items on the floor or the stairs, good lighting in the halls and stairs (good idea to get lights with motion detecting capability so when someone enters a hall or uses the stairs a light will come on, also good in the bathroom)
She may need help in the shower. If your wife or you do not want to take on this task there are agencies that will have caregivers that can shower mom.
If mom qualifies for Hospice a CNA would come at least 2 times a week to shower her. And if equipment is needed Hospice would provide that. (they also provide all the other supplies that are needed)