Meghan, Duchess of Sussex, presented the Duchess of Cambridge with a gold bracelet as a thank you for her help with her wedding to Prince Harry.
In the lead up to Harry and Meghan's wedding at Windsor Castle in 2018 there were rumours of a rift between the two royal in-laws due to a disagreement over flower girl and bridesmaids outfits.
Now, Andrew Morton has now claimed in an added chapter to his unofficial biography, 'Meghan: A Hollywood Princess', that Meghan, 40, and 39-year-old Catherine - who is married to Harry's older brother Prince William - both gave each other gifts as a way of a peace offering, with the former 'Suits' star presenting her sister in-law with a personalised bracelet and Catherine sending a bouquet of flowers and an apology note.
Morton wrote: "The spat concerning the [flower girls'] outfits now behind them, Meghan had since given Kate and her six closest friends gold bracelets designed by Californian jeweller Lisette Polny as a thank-you for their help and support."
Revealing the motivation, he added: "It was an elegant peace offering, both women professional enough to know that there was no gain in showing dissent or disdain."
The wedding of Prince Harry and Meghan Markle took place in 2018, but the pair abandoned their royal duties in early 2020 in favour of a life in California.
The royal expert - who also wrote a biography on Harry and William's late mother Princess Diana titled 'Diana: Her True Story - In Her Own Words' - also dealt with the claim that Catherine, previously known as Kate Middleton before marriage, and Meghan rarely saw each other whilst she and Harry, 37, were still working members of the British Royal Family before they relocated to America in 2020.
He explained this as being a "practical matter as much as anything" and went on to talk of the times the family did spend together.
The biographer stated: "Kate spent weekends and holidays at Anmer Hall, the Cambridges' country home in Norfolk, while Meghan and Harry were approximately three hours' drive away, living in a large, remote, rented property on the Great Tew Estate in Oxfordshire."
Meghan - previously known as Meghan Markle before her marriage to Harry - addressed rumours of a rift between her and Catherine in her and her husband Harry's tell-all interview with Oprah Winfrey, insisting there was no problem between them.
Meghan said: "Kate is a good person. I have seen so much of this idea of polarity - but if you love me you don't need to hate her, and if you love her you don't need to hate me."