The story is a bit more complicated than the meme lets on.
First, while she was certainly very ill after 2 heart attacks, it is unclear if his wife was terminally ill. She was disabled and had mental illness. The husband says that she wanted to die so she left the nursing home. Second, the drug binge went on for 5 days and her condition deteriorated throughout. While she was presumably doing large amounts of meth amphetamines, she also was not taking her prescribed medications. Third, at least in the article that I linked above, the sex occured at the very end and he said that she was unable to speak at that point and she died more or less immediately after. Finally, she died of a meth overdose, and not of her other illnesses.
I'm all for dying on your own terms, and if this was truly her idea or she was fully on board, more power to them. However, the wife can't speak for herself and all we've got is this guy's word.

