We know zero about what Terri wants. So there has to be an equal chance she wants to live as she wants to die. To load it either way from the center is to assume you know something about what she wants. And nobody does. Nonsequiter.
Suicide is illegal and immoral too, notwithstanding the Left's semi-successful efforts to make such niceties a thing of the past, and acceptable in the minds of otherwise sane people like yourself.
Can you honestly say you would want to continue your existence if you were in the same condition of existence? If you knew she wanted die, and could, simply by not expending the effort expended now, you would force her to live?