It's a very difficult situation and i agree with Rowan that you are being attacked for trying to be helpful, however the problem with mental health issues is that the kindest action is twisted and turned around in your head until it becomes somthing entirely different so I think this lady is just unable to see thigns clearly at the moment and thats understandable too.
You were kind and helped her with her workload, she may see that as you seeing that she can't cope and that kindness then becomes a critisism if you follow.
I do think though that you need to get something down on paper to chart every step of what's happened to safeguard yourself.