Our heroine remains Isabel Dalhousie. Her son Charlie is now two. He is beginning to talk more, but by and large his life moves from one joy, visual, aural and oral, to the next. He knows he is loved by his mother Isabel, and his father Jamie - who happens to be younger than his mother by 14 years. His frequent visits to various locations in Edinburgh where he can observe his favourite birds help to keep him happy as do his sighting in the backyard of "Fo" or Reynard the Fox. Charlie has not yet entered the "terrible twos".
You must wait for Number 8 of the serial on the No 2 Ladies' Detective for that. Charlie's caregiver is Grace, whom Charlie also loves. Grace has some unusual interests, including spiritualism that may help to divert Charlie's mother? Charlie has already started to "hit" and his mother is disturbed to find that Grace had let him hit her. He needs to learn right from wrong. How is this accomplished when different people send out different signals to a child?