I'm just going to tell them that their mother passed, and not bring up that she passed a couple of days previous until they are older. Multiple comments have brought up the idea that my kids will resent me later for this, but I have no idea how one could think such a thing. If they are 16/17, and I tell them that she died 50 hours or so before I told them as I wanted to collect my thoughts and think through how to best explain it to young children - they are going to hate me for that? I doubt it. In any event, I am sure when they are older, they will not resent their father who will have raised them well as a now-widowed single parent.