So sorry to hear of the severe problems Mum is encountering.
She should never give up. Amazing recoveries do happen. Smaller recoveries are happening all the time.
I had a straight forward and uncomplicated ischemic stroke. I am lucky as so many strokes are complicated by other issues. It is sometimes possible for me to help others because my injuries are classic and straight forward and so my experiences are sometimes clearer.
Did Mum have a clot or was it a bleed ?
My overwhelming experience is that recovery is slow, slow, slow. I came out of hospital able to talk (a bit) able to walk (a bit) and able to transfer with ease. Mum is not so fortunate.
Can I suggest that you need to be tough and not accept Mum home until things are in place for her. You can not expect to cope with Mum if she can not transfer. The hospital, quite logically, want to get Mum out of hospital. Quite appalling, but the support for stroke injuries is atrocious. We are the cinderellas of the medical world.
When Mum eventually come home she will in the short term be worse than ever. We expect going home to mean we are "better", but that's not how stroke injuries work.
I think you might benefit from speaking to the Stroke Association. Or any local stroke help groups. Your GP (or Mums GP) surgery will have details. The staff can direct you. And likewise the hospital stroke unit will have all sorts of guides and help.
I don't have the stroke association here but my local charitable group are very good at organization and advice for the carers, not just us survivors. Meeting with other carers will be potentially wonderful. They will understand, not many others will understand.
There are many who experience this type of injury, you are not alone with this. Mum being previously healthy will help a great deal. Her age should mean she will recover more quickly.
No one ever knows the time scale. But recovery will go on for years, so don't ever give up.
If you want to read about the ultimate recovery, then Jill Bolte Taylor "A Stroke of Insight" will describe a recovery from very severe stroke injuries. Its a bit technical and its American, but it not a bad read.
To give hope....I went to sleep one night. I was paralysed, could move my right hand but not much else. Couldn't sit myself up, turn my head nor even turnover in bed. I awoke early the next morning and, with physios around me, I got up and walked out the ward. Well staggered rather than walked, but boy that was a marvellous and miraculous day.
Only I can make the recovery. No medics, no relatives can mend me. I have to mend myself. Support is great.
Hope the cavalry will arrive to give you some tips