A federal judge on Tuesday dismissed a defamation lawsuit against Meghan, Duchess of Sussex, after her half sister accused her of spreading “disparaging, hurtful and false” statements in interviews.

Samantha Markle, who shares a father with Meghan, claimed that comments Meghan made in an interview with Oprah Winfrey in 2021 and later in a Netflix documentary series, “Harry & Meghan,” aimed to portray Ms. Markle as “an unwelcome opportunist” who was “weaseling her way” into her famous half sister’s life.

In a 58-page decision, Judge Charlene Edwards Honeywell of the U.S. District Court for the Middle District of Florida found that Ms. Markle had failed to identify any statements that supported her defamation claims. She also ruled that Meghan’s statements were protected either because they were pure opinion or substantially true, or because Ms. Markle had failed to make a case that they were defamatory in the first place.

Meghan and her husband, Prince Harry, spoke in detail to Ms. Winfrey about their split from Britain’s royal family in a CBS special that was broadcast in the United States on March 7, 2021, and in the six-episode Netflix series in 2022, sending shock waves around the world as they accused the royal family of failing to protect them.

Meghan is largely estranged from her half sister and their father, Thomas Markle. When Ms. Winfrey asked Meghan about her relationship with Ms. Markle, who had written a supposed tell-all book about her sister, Meghan demurred.

“I think it would be very hard to ‘tell all’ when you don’t know me,” Meghan said in the interview, adding, “I don’t feel comfortable talking about people that I really don’t know.”