Kate Middleton Was Joined by Special Guests — Her Parents and Brother! — at Her Latest Glam Outing

Matt Frost/ITV/Shutterstock Carole Middleton, Michael Middleton, James Middleton and Alizee Thevenet

Kate Middleton and Prince William made the Royal Variety Performance in London a family night out!

All eyes were on the royal couple, who went full glam for their fourth appearance at the annual charity event on Thursday evening. Joining them in their box were Kate's parents, Carole and Michael Middleton, along with her brother and new sister-in-law, James Middleton and Alizee Thevenet.

Both of the Middleton men looked dashing in classic suits and bow ties, while Carole and Alizee dressed up in evening gowns to watch performances from Ed Sheeran, Rod Stewart, James Blunt as well as the casts of Moulin Rouge, Matilda the Musical and Cirque du Soleil.

The event supports the Royal Variety Charity, of which Queen Elizabeth is patron. The money raised from the show helps hundreds of entertainers throughout the U.K., who need help and assistance as a result of old age, ill-health or hard times.

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Matt Frost/ITV/Shutterstock Prince William, Kate Middleton, Carole Middleton, Michael Middleton, James Middleton and Alizee Thevenet

It's rare for Kate's parents and siblings (she also has a younger sister, Pippa) to join her on royal outings, but the family is close — to each other as well as the royal family. They've even been invited to Balmoral, Queen Elizabeth's Scotland estate where she spends the summer months.

Kate and Prince William were guests at James and Alizee's September wedding in France, where they made sure the attention stayed on the couple.

"Prince William and Kate were there but they did not want to steal the show from the newlyweds, Alizée Thevenet and James Middleton, who is a very nice boy," François Arizzi, mayor of the idyllic hilltop village of Bormes-les-Mimosas who officiated the civil union inside the local town hall, told local publication Var Matin.

"I was able to interact with [William and Kate] in very poor English," the mayor quipped. "We talked about the charms of Bormes-les-Mimosas and its climate, banalities.... It was a simple moment, and I wasn't more impressive than that!"

Kate is close with both of her siblings She joined the rest of her family at therapy sessions when James was seeking care for his depression.

"That was so important because that helped them understand me and how my mind was working. And I think the way the therapy helped me was that I didn't need my family to say, 'What can we do?' The only thing they could do was just come to some of the therapy sessions to start to understand," James explained in an interview with The Telegraph.

Chris Jackson/Getty Prince William and Kate Middleton

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Kate and Prince William, both 39, turned heads upon their arrival. Kate sparkled in a glittering emerald column gown by Jenny Packham, which she also wore during the couple's tour of Pakistan in 2019. The mom of three opted for curly, side-swept locks instead of her usual bouncy blowout.

Meanwhile, William made a fashion statement of his own in a blue velvet tux.

Thursday's event was especially poignant for the Royal Variety Charity as it is the centenary of the Queen being patron. The tradition began with the Queen's grandfather King George V in 1921.