Everyone knows who Prince Charles' sons are - Prince William and Prince Harry. They're really the only two royals we know that is the heir to the throne's children.

But two other people actually call the Prince of Wales their "dad," aside from Meghan Markle and Kate Middleton, and those are the Parker Bowles children.

Camilla Parker Bowles was once married to Andrew Parker Bowles. They have two children.

Prince Harry and Prince William actually have a step-sister.

Laura Lopes

Laura Lopes is the 42-year-old daughter of Camilla, the Duchess of Cornwall and Andrew Parker Bowles.

She grew up in Wiltshire with her brother and were raised as Roman Catholics.

Laura studied History of Art and Marketing at Oxford Brookes University and later became an art curator.

She became a motoring correspondent for Tatler in 2001, along with her brother, Tom Parker Bowles, who was a food columnist in the magazine.

Laura managed The Space Gallery in London in the mid-2000s and later becoming a partner and gallery director for London's Eleven Gallery.

Not a Member of the Royal Family

She attended her mom's wedding to Prince Charles and had an updated family portrait of the Wales' and Cornwalls' back in 2005.

We don't see Laura so often because she is not a member of the royal family. According to an interview Tom gave to "Good Morning Britain," he expressed how he and his sister were "not quite part of the royal family, to be honest."

Tom Parker Bowles added that his mother married into the royal family, so "she's part of it" and said that he and Laure were "the common children, we're just on the side."

Personal Life

Laura Lopes married former Calvin Klein model Harry Lopes in 2006, a year after her mother married Prince Charles.

Harry Lopes is the grandson of a baron and is also related to the wealthy family of Astor.

Laura's Children

She has three children, one girl and twin boys. Her daughter Eliza was a bridesmaid at Prince William and Kate Middleton's royal wedding in 2011.

Eliza was also seen being cradled by the Prince of Wales in the balcony of Buckingham Palace.

Sibling Fights with Prince William

Back when the Parker Bowles children and the Wales children were warming up to each other, it was reported that Prince William and Laura didn't get along back then.

As written by royal author Katie Nicholl on her 2010 book "Harry and William," "William and Laure used to have terrible fights over who was to blame for their broken homes."

She added that the Duke of Cambridge back then would blame Camilla for all the hurt she had caused his mother, which would then send Laura into a rage.

"Laura was not having any of it. She would take a hard line and fire back at William, yelling, 'Your father has ruined my life!'"

According to Robert Jobson, who wrote the book "William's Princess," while both Prince Harry and Prince William seemed like they accepted Camilla, things were much different behind closed doors.

The royal author claims that the brothers were not happy that their father was getting married, but had accepted the fact that it was happening.

"Sure enough, privately, their mood was more one of 'acceptance' and undiluted joy at the prospect of having Camilla as their stepmother.'"

'Duchess' or 'Countess' Laura?

According to Express UK, there's a possibility that Prince Charles may give royal titles to his stepchildren.

So once he ascends to the throne, Laura Lopes and Tom Parker Bowles may become a duchess or a countess, and a duke or a count, respectively.

Tags
Royal uk, Royal family, Prince William, Prince Harry, Camilla parker bowles, Duke of sussex, Duke of Cambridge, Prince Charles