It's Not Always Good

I just finished reading Between Here and April by Deborah Copaken Kogan (2008). The book was sitting on one of the shelves in the "New arrivals" section of the library. There was the title, and the cover showing a child's swing, and a partial view of the faces of a smiling mother and daughter. I had no idea what it was about, and I would never have guessed.
The book tells the story of an adult woman who is the mother of two daughters, but who, because of circumstances in her own life, suddenly remembers another little girl who was her friend in the first grade. The friend suddenly disappears, and no one will tell the younger children why. The "why" is because they were killed by their own mother, who also took her own life while cuddling them. The book is pretty much of a heart breaker, but it gives the reader some insight as to how these things can happen.