Fab Four
Kate Middleton was a proud mom when she saw Prince George at Princess Charlotte at Princess Eugenie's royal wedding. Prince William, Middleton, Prince Harry and Markle react during the wedding ceremony of Britain's Princess Eugenie of York and Jack Brooksbank at St George's Chapel, Windsor Castle, in Windsor, on Oct. 12, 2018. Getty Images/Owen Humphreys

Kate Middleton was very proud of her children.

On Friday, the Duke and Duchess of Cambridge joined Prince Harry, Meghan Markle and the rest of the royal family to witness Princess Eugenie and Jack Brooksbank tie the knot. Prince William and Middleton's children 5-year-old Prince George and 3-year-old Princess Charlotte were among the pageboys and bridesmaids, respectively.

One netizen shared a clip of Middleton's reaction when her children entered the church on Twitter. In the clip, the Duchess of Cambridge is clearly overwhelmed and overjoyed. She seemed to be saying something while smiling that Prince Harry turned to her and smiled.

"Ahah I didn't notice that! And Harry smiling at Catherine, she probably made some kind of noise," one user commented.

Netizens also noticed Princess Beatrice's reaction to the kids. She turned to them and gave them two thumbs up.

"Yes I notice that on the day it was very cute and now knowing of the baby it makes more sense now But only noticed now Beatrice also Autumn philip had s cute reaction to her girls," another netizen wrote.

"Beatrice double thumbs up is so cute too!" another user commented.

According to Harper's Bazaar, Middleton's reaction was understandable as she was excited to see her kids accompanying Princess Eugenie down the aisle. The third-in-line to the throne was very cheeky throughout the ceremony and was even photographed giggling while covering his mouth as his cousin, Savannah Phillip, naughtily tried to distract him.

Prince William and Middleton's children were in high spirits but appeared to be moody during the official photoshoot. In one snap, the little prince and princess were "flagging a little when it came to posing later in the day." The two weren't in their usual smiley selves in the main family photo.

Prince George and Princess Charlotte quickly overcame it. They were seen smiling in the photo that featured the young bridal party with the bride and the groom. In the picture. Prince George could be seen grinning. On the other hand, Princess Charlotte smiled sweet and stirred the royal fans by copying Middleton's signature duchess slant by crossing her legs.