Princess Diana, Prince William and Prince Harry
Princess Diana is pictured with her sons Prince William (left) and Prince Harry on a skiing holiday in Lech, Austria, on March 30, 1993. Jayne Fincher/Princess Diana Archive/Getty Images

Princess Diana previously revealed her sons’ excitement over Christmas in the letter that she wrote to one of her friends.

When Prince William and Prince Harry were still young, the siblings looked forward to the holiday celebrations especially because of all the presents that they usually receive.

In the letter, Princess Diana also gave her pal a piece of advice regarding her relationship with her son Dean’s wife, Jane. She praised her friend for her strength and dedication while waiting for her son to recover from her coma.

“Maybe Dean’s lady feels resentment for not being able to cope with that situation back in August and that can produce guilt and in turn, confusion arrived and people are hurt and now Dean has arrived home and she (Jane) has turned very possessive. You mustn’t worry about it as time will iron things out,” the Princess of Wales wrote.

According to People, Princess Diana’s letter will reportedly be auctioned by Lawrence Auctioneers in Bletchingley, Surrey for over $3,000.

Meanwhile, Princess Diana was very close to Prince William and Prince Harry when she was still alive. In fact, while the late royal was struggling with her marriage to Prince Charles, she gave her eldest son a piece of advice about love and relationships.

"I told William, if you find someone you love in life, you must hang onto it and look after it. And if you are lucky enough to find someone who loves you, then you must protect it,’” Princess Diana said.

The Princess of Wales divorced Prince Charles in 1996 after a 15-year marriage. But just after 11 years, the couple decided to go their separate ways. There were multiple reasons for Prince Charles and Princess Diana’s divorce other than the heir to the throne’s affair with Camilla Parker Bowles.

Prince Charles and Princess Diana were very different from each other. And they didn’t also get to know each other very well before they tied the knot so their union was regarded as a mistake.