I tend to agree with Kathryn K. I think we all do what we know how to do, especially in extreme circumstances. Emotion and instinct override logic in those kinds of situations. It's great to ponder these issues, but we are all predisposed to certain kinds of behaviors, actions and reactions. The death of a parent is going to affect a child in a negative way. The grief of the surviving parent is going to affect a child in a negative way. Every parent wants to shield her child from that kind of sorrow. Unfortunately, whatever a parent's reaction might be, nothing can truly "protect" a child in that situation.
I think it's interesting that the author chose to show two such extreme methods of dealing with grief and loss.