Yes, she is apparently 49 and so you're correct that in this case, her disabilities (partial blindness, cognitive and mobility issues and cerebral palsy) are not age related. My mum's disabilities are age related. Still - disabilities.
To answer your second question, my mum might do so if they appeared to be approaching her at speed. That would scare her. She, like many older people, or those with disabilities, don't trust their balance when they perceive something approaching them in this way.
I think I made it abundantly clear in my post that I think it was an awful event and was explaining giving an opinion on what might result in somebody reacting in this way. Thank you for pointing out that if my mother did these things and someone died as a result, that she could expect to be charged. I think I worked that out. Rubbing my couple of braincells together, you know, thanks for helping me out there :) Still - I think it's ok to not see people entirely as BAD or GOOD and understand why things might have happened, even in horrendous events.
The woman in this case is certainly being punished. Conversely though - most cyclists who result in people falling or being injured, probably do entirely get away with it - even when they've yelled ON YOUR RIGHT in your ear two seconds before zooming by and are oblivious to a fall they've caused.
On the plus side, aggressive behavior on Mumsnet doesn't result into one of us falling into traffic - so, that's something.