Interesting story, a speculative look at the difficult dilemma of what to do about a loved one in a coma.
As she was giving the threads to her daughter and her daughter was reacting, my interpretation of that was that the reaction didn't necessarily meaningful. Certain kinds of stimulus will even make a corpse react (applying electrical stimulation to tense the muscles) and I thought this was much the same thing.
I'm not sure I understood what was meant by the daughter's hand producing a thread at the end.