You seem to be guilty of the same thing you accuse the doctors of doing. You have no idea what was going in her mind (or not going). You have no idea if she was still suffering. You have no idea if she wanted to die.
You're the "compassionate killing is wrong, we must preserve life at all cost and quality of life be damned" type of person, and it's simply impossible to have a conversation when your view of the world is so black and white.
Karen clearly did not wish to die at all; nor did her parents or physicians wish to deny her a right to life.
Her parents and physicians all agreed (after the fact) that the removal of the machine proved to relieve her immediate suffering and distress, just by judging those outward signs and her struggles against the relentlessly opinionated machine.
There is nothing “compassionate” about killing; it is an oxymoron and a political slogan for eugenicists. You seem to desire that some assassin had stepped up and murdered Karen against everyone’s wishes, and against the law. You and your ilk have a similar mindset to Dr. Mengele, and y’all seem very very proud of that mindset.