If this were true, we think it'd be the most groundbreaking news, ever. There have been rumors going around for years that Princess Diana has a secret daughter, but could it really be accurate? Yes, that would mean Princess Diana's other children, Prince William and Prince Harry, have a sister, too! Scroll down for all the details on the rumors.

Did Princess Diana have a daughter?

Thanks to Globe magazine some royal fans are convinced that the late royal — she died in August 1997 after a fatal car crash — is a mom to a girl named Sarah (who is in her 30s) that lives in the US. However, so many are curious to know how she could possibly have a child who is older than her son, Prince William, 35.

According to the tabloid, before Diana married her ex-husband, Prince Charles, back in July 1981, Queen Elizabeth made the then-19-year-old test out her fertility! What?! Once she proved she was able to bear a child with Charles' sperm, the fertilized eggs were ordered to be destroyed and the couple was then allowed to announce their royal engagement to the world.

And here comes the plot twist. Apparently one of the doctors kept one of the fertilized eggs to implant into his own wife. Crazy! The girl — who was allegedly born in October 1981 — grew up being called Diana's "dead ringer." Her parents were killed in a car accident when she was in her 20s, and she soon learned from reading a diary that she was a product of the royal couple. Now, after trying to figure out the truth about her life, she lives with a hidden identity. The most insane part? She's reportedly met William's wife, Kate Middleton. So bizarre if you ask us…

princess diana prince charles kids getty images

Diana and Charles with William and Harry in the '80s.

In a previous resurfaced interview, Diana claimed her marriage to Charles fell apart because the couple never had a daughter even though Princess Diana and Prince Charles had two kids. "He wanted two children and he wanted a girl," she explained. Charles was disappointed when he saw Prince Harry was a boy at birth (Diana kept the gender a secret up until then). Diana claims he said, "Oh God, it's a boy," when he met him, followed by, "and he's even got red hair." So sad…

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