Ms Markle, 37, now the Duchess of Sussex, wanted to wear a tiara set with emeralds, according to The Sun.
"He will get down on his knees and crawl about with them for hours, you know making amusing noises and laughing and my grandchildren adore him, absolutely adore him", she says. "She gets what tiara she's given by me".
"There was a very heated exchange that prompted the Queen to speak to Harry".
In the end she wore a diamond bandeau tiara that was made for Queen Mary in 1932.
Another thing that the Queen and Meghan were in disagreement of before the wedding was Meghan's decision to wear a veil. It was bequeathed to the Queen in 1953 and had not been seen again in public...
The Charles at 70 book said the Queen and the former Suit's actress had bonded over their love of dogs. Recently, there were a few reports that before their wedding, Harry told the Royal staff that Meghan gets what she wants.
'Harry and I had gone to Buckingham Palace to meet with Her Majesty The Queen to select one of the options that were there, which was an incredibly surreal day as you can imagine.
"He reads Harry Potter and he can do all the different voices and I think children really appreciate that".
Harry said the tiara was the one that "looked the best on you, without question", adding that it was an "incredible loan" by his grandmother.