NOX, that is a dreadfully sad story.
I suppose what *we* think matters not a jot. Just so long as it was their own decision. I believe it is nigh impossible to put oneself in another's position/circumstance. I cannot begin to contemplate the enormity of how painful they saw their future. Whilst neither twin was ill in the conventional sense, goodness knows what would have become of their mental state in time. I have always been of the 'quality rather than quantity' school.
To sort out someone else's problems, life style etc., is so easy but doing it for ourselves ...
I hope they RIP