There is not a single person here that can honestly say that we know for sure that this is not exactly what Terri said she would want. The only we know for certain is that she didn't put it in writting.
Civilized people don't put others to death because their wishes are ambiguous. Valuing human life is the core of what distinguishes us from savages. When you don't know, you are compelled to err on the side of life. Once someone is dead there is no do-over.
so why not err on the side of life? death is irreversable.
if you screw up, you can't take it back. Let her get well enough to speak again (she was speaking when put into the hospice), and let her say what she wants..