Sources say the Monarch has made the "very thoughtful gesture" towards Ragland because she respects her so much.
Queen Elizabeth II has reportedly invited Doria Ragland over to Great Britain for Christmas.
Kate's family have never been asked to join the royals at the queen's private home and have only attended the morning church service with the family - so Doria will be the first non-royal to spend the day at the estate, Glamour writes.
A spokesperson for Buckingham Palace has so far declined to comment.
Give Him Big Credit - Mauricio Pochettino Salutes Member of Backroom Staff
The whole season we've been grinding out results here and there. "We had Barcelona, Inter and Spurs so it was a very hard group". Spurs have one point from three games and will be eliminated if they lose on Tuesday and Inter Milan beat Barcelona.
Google working on fix for Pixel 3 memory management problems
In our in-depth Google Pixel 3 review , we dove into all the reasons these new Pixel phones are the best Pixels yet. However, the APK version is available for Pixel series users to get a taste of what the Night Sight mode brings.
Indonesia plane crash: Jet had airspeed problems on final four flights
Tjahjono said his agency was asking Boeing and the United States what action to take to prevent similar problems around the world. Lion Air is one of the youngest airlines in Indonesia but has rapidly grown, expanding its flights in Southeast Asia.
Following weeks of drama surrounding Meghan's father Thomas Markle and her extended and estranged family members in the US, Doria was praised for her composed and graceful appearance at the royal wedding.
He later said he had apologised to both Harry and Meghan and denied staging the shots for money, insisting they were taken in a bid to "change his image".
Eager to impress, Meghan, 37, arrived to their January 2017 meeting at Kensington Palace armed with a present in honor of Kate's recent birthday.
Doria introduced herself to guests on the day as "Meg's mom".
Meghan and her mum, Doria Ragland, are said to have a close relationship.