It would have been more humane to put a slug in her head than let starve like she did. Try this with horse or a dog and PETA and every lefty organization would be all over it.
I agree. Unfortunately active euthanasia is not legal in the United States. I do not doubt that the same people who are decrying how painful it is to die of dehydration (if she could have felt it, of course, which she was almost certainly incapable of) are the same sort of people who also decry active euthanasia.
I believe they gave her morphine in the end, to comfort the family rather than Terry herself.