I don't know what her real medical condition is, and I accept the possibility the doctors on either side are correct. But the case still troubles me and I wouldn't remove the tube at this point due to all the familiar facts - differences in medical opinions and observations, the husband's estrangement, and teh parents' desire to provide additional care.
That's what I think. There's way too much doubt.
I guess in lieu of not being able to know, we should err on the side of letting her live.