Samantha Markle changed her name after Meghan started dating Prince Harry

• Samantha Grant changed her name to Samantha Markle after Meghan Markle started dating Prince Harry.
• Meghan Markle told Oprah she hadn't seen her half-sister in almost 20 years.
• In February, Samantha released a "tell-all" book about Meghan despite the distant relationship.

Meghan Markle's half-sister, Samantha Markle, changed her last name to match Meghan's after she started dating Prince Harry.

Samantha Markle, who previously went by Samantha Grant, and the Duchess of Sussex are related through their father. Samantha has been a vocal critic of the duchess since she became connected to the royal family, and she published a tell-all book in February titled "The Diary of Princess Pushy's Sister Part 1."

However, in new footage of her bombshell interview with Oprah that was aired on "CBS This Morning," Meghan said it would be difficult for Samantha to write an accurate tell-all because she doesn't know her.

"I think it would be very hard to tell all when you don't know me," Meghan told Oprah, saying that she and Samantha were never close.

"I grew up as an only child, which everyone who grew up around me knows," she said. "I wished I had siblings. I would've loved to have had siblings. That's why I'm so excited to be pregnant, so that Archie has someone."

Meghan's description of her relationship with her half-sister is quite different from how Samantha depicts it.

"You know, people don't understand we were very much integrated into each other's lives. She was the baby in our household, we never addressed each other as half-sister," Samantha said during an interview with "Good Morning Britain" in 2018. "We had the same father, she was in our lives. We had two households, there was a bridge. We were united. So I thought, why doesn't she call me?"

Meghan went on to tell Oprah that she and Samantha hadn't seen each other in almost 20 years.

"The last time I saw her must've been at least 18 or 19 years ago, and before that, 10 years before that," she said, adding that Samantha doesn't know her.

Meghan also pointed out that Samantha only started using the last name Markle in the last few years, seeming to suggest Samantha was using the name because of its connection to the duchess.

"She changed her last name back to Markle in - I think she was in her early 50s at that time - only when I started dating Harry," the duchess told Oprah. "So I think that says enough."

"When you talk about betrayal, betrayal comes from someone that you have a relationship with," she said of her half-sister. "I don't feel comfortable talking about people that I really don't know."

In 2018, Samantha told the Daily Mail that she suggested her father stage paparazzi photos ahead of Harry and Meghan's wedding for positive press.