In an interview on Radio 4 in 2017, the Duke of Sussex spoke about Meghan's first Christmas at Sandringham with the Royal family.
He said: "She’s done an amazing job, you know it’s the family I suppose she’s never had."
In the documentary titled, Meghan And The Markles: A Family At War, Samantha said: "The first thing I thought was I don’t think Harry has been given the full story.
"Something was not right. Though we weren’t the classic family together on schedule for every holiday, we were family.
"Then we questioned why… why would she be embarrassed about her family? Why would you need to set the stage differently?
"It was starting to feel like she wasn’t reaching out to the family."
Samantha also questioned the motives behind a letter sent by the 37-year-old Duchess to her father Thomas calling it “strategic” and “contrived.”
In the letter, which Thomas made public, the Duchess pleaded with her father to stop speaking to the press.
Meghan write: "If you love me, as you tell the press you do, please stop. Please allow us to live our lives in peace."
She accused her father of breaking her heart "into a million pieces" by his actions.
But Samantha, who was not invited the Royal Wedding, said: “That letter was strategic, it was so elegantly written and contrived.
“She was basically saying that my dad had been a liar and that I was a liar.”
Samantha, who changed her name back to Markle from her married name Grant following her sister’s engagement, claims her father has “evidence” that Meghan had not contacted him prior to sending the note.
Speaking about how the Duchess has treated Thomas, she said: "She doesn't have a heart or she would have been doing everything she could to make him comfortable and reciprocate, and be loving, and gracious and make sure he's comfortable in his old age."
Responding to accusations by Meghan that she had lied about her, Samantha said: "I pointed out that humanitarians don't treat their father coldly. Was that a lie? No, because the world watched it happen to my dad and the world watched her do it."