Her last visit to the country was in 1997, shortly before her death in Paris, to help raise funds for a cancer centre Khan built in Lahore.
Prince Harry on his visit is expected to remotely detonate a mine.
The Joe DiPietro-David Bryan production focuses on Diana's marriage to Prince Charles and the pair's separation.
The bemused father said, 'Billy (aged two at this time) pointed and said, 'Look! It's me when I was a princess','when he spotted Princess Diana on a card.
The ivory silk crepe gown features silk tulle detailing and sheer material on the shoulder. She paired the dress with the same colour evening gloves and styled her hair in an updo.
He said dealing with the loss of his mother - who died in a 1997 car crash - meant he felt he could relate to others who had suffered a bereavement.
Newcomer Emma Corin has been roped in to play the role of young princess Diana in Netflix’s hit royal drama, The Crown.
There was something old and something new in the ring Meghan Markle!