Your Mum needs expert help.
Please ring the helpline and the Parkinson's nurse.
There are meds that can help overnight and bed aids that can be provided.
Don't suffer alone...there are people who can help yuo and your Mum to be more comfortable.
The softest memory foam mattress and pillows (2) gave me blessed relief in my struggles with parky also satin or silk sheets alow easier movement and prevent getting into a knot this combination certainly worked for me, but make sure you choose the softest as they are graded. I also purchased a ajustable bed which allows the optimum position for restful sleep
I hope this works for your Mum
Kindest Regards Fed