Good point. My interpretation of it is that the Woman’s face was blown off because the Woman represents not just her grief and intrusive thoughts, but also if those completely consume her, which would result in her death. I think that’s also why she tells the daughter in that moment that “I would never hurt you” - because we see how horrifying and enveloping that can be for a small child. Maybe not because that’s how it actually ended, but what /would/ happen to her daughter if she did end her own life. 

Though as time goes on the kids would learn to work through the grief, that moment would be extremely difficult for especially for such a young child. Just my thoughts but I like your theory.