They cite that the smaller size of St. George's Chapel at Windsor Castle and Prince Harry's place in the line of succession to the English throne are the two main reasons.
The 12-year-old of Dronfield Woodhouse, near Sheffield, has been recovering from trauma after witnessing the aftermath of the bombing at Manchester Arena.
Kensington Palace on Tuesday named some of the 1,200 people, chosen due to their strong leadership and community service, who have been invited into the grounds of Windsor Castle on the wedding day to join the celebrations.
The only prerequisite for an invite, Kensington explained at the time, was that "the people chosen are from a broad range of backgrounds and ages, including young people who have shown strong leadership, and those who have served their communities".
According to its creator, she was inspired by a mug commemorating the marriage of Prince William and Kate Middleton.
The 52-year-old from Haringey, London, will take her 15-year-old son Jude Anomneze-Collins as her plus one, after he made a heartfelt plea to attend alongside her.
She explained "He used to watch Suits".
"I'm planning on going in very formal attire". Meghan Markle is a divorcee.
StreetGames offers sport activities to young people to transform their lives.
Ex-Royal Irish Regiment soldier Philip Gillespie (pictured below), who lost his right leg during a tour of Afghanistan in 2011, said it felt a "wee bit surreal" to receive an invite in the post.
Also attending will be Reuben Litherland, 14, a deaf pupil who started sign language classes at his school, Saint Benedict Catholic Academy in Derby.
However, The Sun has surmised that if Harry and Meghan invited the Obamas but did not invite the Trumps, this could potentially cause political ramifications for Theresa May, who is dealing with Brexit. Though they better be careful: fantastic people like this might just outshine the bride and groom.