It depends on her degree of disability, rather that her disease. She would be required to have a specific medical examination, arranged by the DHSS, to determine this.

She will have to claim DLA ( disability living allowance) if she is successful then she can use the money for a motability car.

Hiya,
I am so sorry to hear about your auntie this is a horrible disease, and very very dibilitating. My dad is currently suffering from this condition, so i know what it is like for you. But yes you auntie can get mobility depends on person preference and also financial situation. I wish you the absolute best for you and your auntie and if you ever need to talk that applies to both you and your auntie please dont hesitate to contact with me the last thing you need is to be coping alone at this time and i will be more than happy to be there for you both.
God Bless
Hope i helped
x