The royal wedding is 50 days away, and we're starting to learn who Prince Harry and Meghan Markle are including in their big day. The royal couple invited 2,600 people from all walks of life to the celebration on May 19, but Kensington Palace has been tight-lipped about the guest list.

One lucky guest has been revealed: Daniella Timperley, a high school student from Ireland, reports CBS News correspondent Jonathan Vigliotti. Timperley's grammar school announced on Twitter the student was invited for her extensive charity work. She will be one of the 600 guests attending the wedding service at St. George's Chapel before making their way to a lunchtime reception given by the queen at St. George's hall. A larger group will be welcomed to the grounds of Windsor Castle to watch them arrive and to see their carriage procession close up.

Sunday Times royal correspondent Roya Nikkhah told "CBS This Morning" the prince not only invited guests from Malawi, with whom he worked on a conservation project, but also Prince Seeiso of Lesotho, who co-founded the charity Sentebale with Prince Harry to help children with HIV.

In addition, "Nacho Figueras, a very famous Argentinean polo player, is coming. And also in sort of a quite poignant move, Meghan and Harry have invited survivors of the Grenfell fire tragedy," Nikkhah added, referencing the public housing fire in London that killed at least 80 people last June. "Community members and survivors of that will be inside St. George's Chapel."

Others in the international guest list will include "a healthy dose" of Markle's friends from the cast of "Suits" and her stylist, Jessica Mulroney, Nikkhah said.

One person who has not been invited to the wedding – and this might be a surprise – is Sir Elton John, who was close to Harry's mother, Princess Diana. He joked that he lives so close to the chapel, he could just roll down the hill.

More than 250 members of the armed forces will carry out ceremonial duties in the wedding procession. Prince Harry served in the army for 10 years, including two tours in Afghanistan, and is the captain general of the Royal Marines.

The invitations allow for military uniforms to be worn. It's still unclear if Prince Harry will don a similar uniform to the one he wore at Prince William's wedding or a less formal morning suit.

Asked whether there's talk of the couple honoring Princess Diana during the celebrations, Nikkhah said it's "pretty much assumed that it would happen," like with Prince William and Duchess Kate's nuptials.

"There's no doubt Harry's very keen to keep Diana's memory involved in his wedding," she said.

There will be multiple opportunities for the public to share the wedding with the royal couple. Harry and Meghan are making it a "very public 'people's wedding,'" Nikkhah said.

A subtle detail on the invite has been catching some attention. Markle is referred to as "Ms." instead of miss, another modern move for the royal household.

Invited royal wedding guests we know so far: