The late Princess Diana’s brother, Earl Charles Spencer, is looking back at how her two sons’ grieved her tragic death at age 36. “I do sometimes wonder with the situation, if I can call it that, … how much it is connected to this very sad time,” Charles, 62, told CBS Sunday Mornings when discussing nephew Prince Harry’s “feelings” in a preview of his Sunday, September 20, sit-down interview with the outlet. “He was so young, he was also so tiny. I remember walking beside him and thinking, ‘This little boy shouldn’t have to walk behind his mother’s coffin.’” Diana was tragically killed in a fatal Paris car crash in 1997. In addition to…