Meghan Markle may not be an official member of the royal family just yet, but that doesn’t mean she isn’t already beloved by the Windsor family.

On Monday evening, Markle will make her first official appearance alongside Queen Elizabeth II at the Commonwealth Day service at Westminster Abbey, which marks the largest annual inter-faith gathering in the U.K. Markle's presence at the event alongside the reigning monarch, Vanity Fair noted, shows “just how warmly” she’s been welcomed into the family.

“She is already effectively being treated as a full-blown member of the royal family, even if she hasn't married Prince Harry yet,” Roya Nikkhah, royal correspondent for The Sunday Times, told NBC. “I think that gives you an indication of just how warmly she has been welcomed into the fold, but also effectively she is living as a member of the royal family.”

Of course, the event isn’t just for Markle and the Queen. Prince Harry, Prince William, and Kate Middleton will also be in attendance. According to NBC, there will also be 2,000 other people at the inter-faith event, including Prime Minister Theresa May and singer Liam Payne.

Beyond spending quality time with the Queen, Markle has also been getting in plenty of family time with her future brother-in-law Prince William and his wife, Kate. In late February, she made her first official appearance with Harry, William, and Kate at the inaugural Royal Foundation Forum, where they were quickly dubbed “the Fab 4.”

At the event, the foursome discussed their charitable ambitions and what it’s like to work together as a family. When the event presenter Tina Daheley asked if they “ever have disagreements,” Prince William was the first to react with a silly, "Ohhhh yes.” Harry quickly added that they were “healthy disagreements” and in turn joked that they couldn’t remember what the fights were about because they come “thick and fast.”

Though they don't sound like anything too serious, hopefully the Fab 4 can resolve any major disagreements before Kate and William welcome their third child next month, and before Harry and Meghan walk down the aisle in May.