The Princess of Wales' sister, Pippa Middleton, was her rock throughout her royal wedding to Prince William in 2011, showing her unwavering support as her Maid of Honour.
When the time came for Pippa to wed her love, hedge fund manager James Matthews, six years later, the roles reversed. Kate, who was now a mother-of-two, was in charge of leading the flower girls and page boys in and out of the church during her sister's nuptials.
© GettyPrince George was a page boy alongside Casimir Tatos, Edward Sebire and William Ward, while his younger sister Princess Charlotte was one of four flower girls for Pippa's big day, which took place on 20 May 2017 at St Mark's Church, Englefield.
The Princess of Wales' firm but fair parenting caught on camera
As the newlywed bride and groom emerged from the church, cameras caught sight of Pippa's stunning lace Giles Deacon wedding dress and handmade Maidenhair Fern tiara.
They also captured a visibly flustered Kate, who was seen trying to calm down a very over-excited young bridal party outside the church. Watch the video below…
The Princess' parenting skills were on full display as she led the children out the church and into a car following the ceremony – a task she had previously admitted worried her.
© GettyStaying cool and collected, the royal knelt down to Princess Charlotte's level to reason with her as she stamped her feet.
© GettyIn another sweet moment, Kate placed a hand on her son George's head which instantly made the young royal stop his playful antics. Comforting her children, Kate held her daughter's hand and rubbed her son's back as they waited for a car to arrive to transport them from the church.
Supernanny reacts to the Prince and Princess of Wales' parenting
© GettyIt's not the first time the Princess of Wales' parenting has been tested in public. At the late Queen Elizabeth II's Platinum Jubilee celebrations, Prince Louis memorably caused chaos in the royal box as he pulled faces, threw a tantrum, and climbed onto the lap of his grandpa King Charles at the historic event.
"Prince William and Princess Kate are a credit to their children," Jo Frost, AKA Channel 4's former Supernanny commented at the time.
© Max Mumby/IndigoSpeaking about Prince Louis' playful behaviour, she continued: "His parents navigate their son's behaviour in public settings, they balance room, holding space for Prince Louis to be himself emotionally, whilst instilling the importance of social conduct in public settings and I believe this should be recognised and complemented as many families do the same in life.
"I'm more impressed with how the Prince and Princess of Wales continue to be such impressive parenting role models to our modern parents today, they are open about their own struggles as parents and like all parents out there continue to strive to do their very best in raising their young."
