It's too late to make an estate plan after you become terminally ill or die. Your children won't be able to make a contingency if you die or become incapacitated. Only you, and only while you are alive and coherent, can make an Estate Plan and create a Living Trust. Your wishes, which you thought "everyone knew," would possibly have no legal weight without the carefully prepared, completely signed, and observed documents in a complete Estate Plan. This is something you could do right now.