telling a 6year old?

[MomWhereIsMy]

Should I tell my D's that his grandmother is terminally sick or is he too young? He knows that she is sick and has seen her lose the use of her legs.

Unfortunately treatment has not worked and it is now palliative care. I just fear that if I tell him it upsets him and it could be next month or five years before anything happens.

Are there any good books out there?

Thank you.