My parents are still 'in' and in their late sixties. Dad still window cleaning of course. My two brothers and sister, who all left years before me, tell me it's not worth kicking away our parents 'comfort zone' at this stage in their lives.
On a side issue:
First of all, I am somewhatdismayed that your sibs believe there is a cut-off date for your folks being able to handle the truth about the 'troof.' And second of all, that it is late sixties! Maybe your folks would like to enjoy life a bit while they still can instead of hauling their wrinkled old asses to the KH three times a week and out in FS.
Okay - had to get that off my chest - carry on.