I too suffer with M.S and I am currently on steroid treatment (500mg) a day so I know just how your mum is feeling. I have only been diagnosed for three years and I am already relyant on a walking stick, a walker, and at times a wheelchair.
Yes I was a toker before I became ill, but over time I have discovered that cannabis is the only thing that doesn't cos me any side affects. A wee toke helps control my muscle spasims, which is a great relief when useing a cathater. I also suffer seizures too which are so damn painful, but instead of having a jab of morphine my hubby rolls me a "J" and this gives me great pain relief without horrible side affects that morphine gives me.

I do hope that in the near future your mum will come to terms with the fact that she is not breaking the law, she is giving herself quality of life. No one has the right to stand in judgement of her or anyone else for using cannabis to help them with aliments of any life changing illnesses.
Please let us know how things work out...

KIND REGARDS........KIWI xxxx