Kate Middleton and Meghan Markle
Kate Middleton may wear a familiar tiara and earrings on Prince Harry and Meghan Markle's royal wedding. Pictured: Markle and Middleton attend the first annual Royal Foundation Forum held at Aviva on Feb. 28, 2018 in London. Getty Images/Chris Jackson

Kate Middleton may sport a familiar look at Prince Harry and Meghan Markle's royal wedding.

Many are wondering if the Duchess of Cambridge will upstage Markle on her big day. According to an expert, Middleton has a vast collection of jewelry for the said occasion. However, she will likely rewear the tiara she wore on her royal wedding to Prince Harry and Markle's nuptials.

"Duchess Kate has one of the most extensive and most impressive collections of jewellery to choose from around the world. She not only has her personal collection, but there are also many pieces in the Royal collection she has the option to loan," Grant Moble told Now to Love.

"This is one of the reasons that you do not often see her repeating the same jewellery. Although it is impossible to be sure, when it comes to her choices for the upcoming royal wedding, I would say the below pieces have a great chance to be seen," he continued.

Moble believes that Middleton will opt for the Cartier Halo tiara for the upcoming royal wedding. According to him, the Duchess usually chooses the diamond jewellery due to its immense meaning.

In addition, Prince William's wife may also wear the Robinson Pelham earrings that she also wore on her big day. "The earrings are not large or showy, but that's just classic Kate, plus they match the Halo tiara perfectly," Moble added.

However, according to People, Middleton's Cartier Halo tiara will be on display at the National Gallery of Australia from March 30 through July 22. Thus, the Duchess is unlikely to rewear it at Prince Harry and Markle's nuptials.

According to the official website for the jewelry show: "Cartier: The Exhibition," Middleton's Halo tiara will be one of the 300 tiaras, necklaces, brooches and earrings that will be featured in the exhibit.

In related news, Prince William and Middleton will not bring Prince Louis to the royal wedding. However, Prince George and Princess Charlotte will be there as part of the entourage. The 4-year-old prince is expected to be the pageboy while the 3-year-old princess will be among the bridesmaids.

Prince Harry and Markle will tie the knot on May 19 at St. George's Chapel at Windsor Castle.