"Since when does God demand we do all we can to maintain a life when there is no hope of them recovering."
God says ALL life is precious.
Are you an expert on what is and isn't a viable life?
"Who says we have to keep a person alive in a terribly disabled state..when half their brain has liquified and they have no chance of becoming a whole person again?"
We don't know that she would stay in this state forever now do we? Her "husband" has prevented anyone from working with her in any form of rehad that would bring her back to a better state than what she is in right now.
"There are no easy answers for these questions."
Agreed.
God says ALL life is precious.
But God doesn't preserve ALL life at all costs.
In fact God allows ALL kinds of people to starve and die of all sorts of infirmity.
Does this make God evil?
How then can you demand a higher standard of man than we can expect from God?
I think your judgments are not fair.