By the age of 5, Princess Diana's home had become a battleground for her parents' marriage. Her mother left the family home in 1967 and separated from Diana's father. Her parents eventually divorced in 1969 after a custody battle. "It was a very unhappy childhood. Always seeing our mum crying," Diana admitted in recordings published by the Daily Mail. "Daddy never spoke to us about it — we could never ask questions. Very unstable, the whole thing."

There were rumors of an affair and physical abuse, but Diana's brother, Charles, presented another theory of marital demise to the Sunday Times. Following the death of a newborn boy, John, in 1960 and the birth of a third healthy girl, Diana, in 1961, their father put an enormous amount of pressure on Frances to produce a male heir. The family convinced Frances to undergo gynecological testing to determine why she could not produce a male and Charles believes that Frances and John never got over this traumatic period.

Diana recollected traumatic interactions from her childhood. "I remember seeing my father slap my mother across the face," she confessed. "I was hiding behind the door, and Mummy was crying. I remember Mummy crying an awful lot." Once Frances left, Diana's brother recalled an image of a devastated young girl who would wait by the door for her mother to come home to no avail.