Meghan Markle's mother "expected" to spend part of the Christmas holidays with her daughter and Prince Harry

Meghan Markle and Prince Harry's first vacation as a married couple will surely be memorable.

A source told ET that Meghan's mother, Doria Ragland, should spend part of her vacation with her pregnant daughter and son-in-law. Doria is expected to receive an invitation to go to church with the royal family in Sandringham, the royal estate of Norfolk, England, where the royal family traditionally celebrates the holiday.

Meghan and her mother have remained particularly close, while the relationship between Megan and her father, Thomas Markle, remains tense.

"Doria's quiet dignity and grace at the royal wedding earned her tremendous respect from Meghan's new in-laws," the source told ET.

The source also said that Harry "loved his mother-in-law very much," and she spends time with her couple, including two long holidays this summer.

In addition, adds Doria, Doria will play a leading role in the education and life of their newborn.

Queen Elizabeth, Harry's grandmother, remarkably broke the protocol last year by inviting Meghan as the first fiancée to attend Christmas with the royal family before her marriage to Harry in May. And according to the Sunday Express, the queen again broke the protocol by inviting Doria to Christmas dinner this year.

In contrast, Kate Middleton's parents were also invited to Sandringham's Christmas Mass, but usually stay with their daughter and Prince William in their nearby house nearby. Kate and William alternated their holidays, spending Christmas in Sandringham and his family in Bucklebury.

"It's a mark of Queen's respect for Meghan and a recognition that she has no other relationship in this country – unlike Kate who has the support of a very close family," said a source to the British press.

Meghan and Harry recently completed their first official Royal Tour in New Zealand. Look below: