'To murder' is unlawful. To insist this is murder is hyperbole. I wouldn't be so opposed if you said 'to kill', but thats not right either. She is lawfully being allowed to die. May she rest in peace.
If any human being were subject to the same restraint as Terri Schiavo - complete denial of food and water - then you too would starve and die, just as she is. Under those circumstances I bet there would be no doubt in your mind that what was happening to you was murder.