Kate, on the other hand, came across as more serious, her expression hinting at tension as she kept her focus on the match.

As the pair took their seats—Kate positioned next to Rob Udwin, president of the RFU—they seemed to share a whispered exchange filled with nervous energy.
Turning to Rob, Kate was reportedly seen saying, according to a lip reader: “He is nervous, I can see he is.”
It’s unclear which player they were referring to, but Rob appeared to reassure her, responding: “He is certainly not an amateur.”
“He certainly is not,” Kate agreed, before Rob added further praise: “He is very impressive.”
With a nod, Kate remarked: “He plays very well as I imagined.”
According to body language expert Judi, the tension seemed to fade as England gained the upper hand against Wales. Kate’s more playful side emerged, marked by a mischievous smile that hinted at her enjoyment of the friendly rivalry—something that didn’t go unnoticed by William.
“As the scores stacked up in England’s favour, it was Kate flashing a ‘naughty’ dimpled smile, while William stuck to his puckered-mouth grins, suggesting he was still enjoying the banter.”