“This is not a spontaneous or intellectually creative woman but a consummate performer and strategist.
“There is a strong right slant and her letters have often been retraced.
"There is enormous emotion as well as energy but she is both self aware and self orientated.
“However she suffers from anxiety and in this instance her usual regularity and over control of pen strokes does show some wavering and a slight uneven baseline - she is showing some wavering of self control.
"But not much.
The letters sent by the 37-year-old to her troubled father read: "Dad, I'm so heartbroken. I love you. I have one father. Please stop victimising me through the media so we can repair our relationship.”
According to People, a close friend said, Thomas, 74, wrote a letter back which requested they do a father-daughter photo shoot.
She said her Dad had broken her heart “into a million pieces” by giving interviews to the press, attacking her husband Prince Harry and fabricating stories.