ive had 4…

At 4yo mine were able to understand the finality… you dont need to great detail about death… but the temporary nature of life is not terribly hard to grasp. I was always of the mind that you should answer any question asked truthfully… but obviously age appropriate.

i always found i was making a bigger deal of %concept% than was necessary

also… its gunna suck… youre going to feel your own pain as well as theirs