Hi Rincewind, Welcome to Talking Point (TP).
Do you have an OT? As they will advise on what equipment is available to help you with your mum. Or you maybe need to have an assessment done.
We have problems similar to yours with my MIL. We now have a lifting belt which is a wide padded belt that is adjustable and has a number of loops around it and is a great help for making MIL feel secure when standing. We also have two commodes one upstairs one down. They both wheel over the toilet which is a great help. Through the day we bring the commode to her chair and transfer her on to the commode then wheel her into the toilet. We also have a turning stand which we use all the time to transfer her from commode to chair and vice versa.
She can walk with the aid of a zimmer frame and the lifting belt on and me supporting her but will sometimes have a panic attack and then can't move. I think its all to do with the dementia and forgetting what to do. She had fallen a great number of times in the past before they came to live with us and this seems to have really frightened her. You need to have all the patience in the world and take things very slowly (which sometimes is easier said that done).
The turning stand and lifting belt are absolute godsends as I can now manage MIL on my own when needs must.
Hope this helps. Take care xx