Stem cell researchers are working on their use in multiple system atrophy, however the studies have not yet progressed to humans. Please check the link below they have info on the research that is being done.
I am not a Doctor just a newer diagnosed patient. I am 43 and know what your going through. I can tell you I have done the why me, the depression thing and so on.
In my own personal experience stress makes my symptoms worse. And though it's easier said then done try to help your Aunt achieve a positive outlook it really helps.
There isn't treatment available at this time but that doesn't mean anyone should be telling her to give up. I truly believe anything is possible, I make jokes to my 16 year old saying just think when I am in a wheel chair we can get to the front of the line at amusement parks. I know this may sound ridiculous but when we focus on the positive it makes our minds react differently. I hope that you find the answers you seek and as Michael J. Fox says always look up!
My thoughts are with your family