Charlotte, 7, joined her mum and dad at the Sandwell Aquatics Centre to watch the swimming events.
She giggled, clapped and pulled a series of funny faces as the playful youngster delighted the Midlands crowd.
Prince William and Kate, visibly delighted in the company of their daughter, beamed with pride as they watched on.
At one point, Kate tenderly tucked locks of her hair behind her ear which had fallen from her plaits – while Charlotte stuck her tongue out.
Princess Charlotte with Kate, Duchess of Cambridge and Prince William
Jacob King
Princess Charlotte was visibly delighted with her parents
Jacob King
William and Kate arrived on Tuesday, shortly after the Earl and Countess of Wessex and their children, Lady Louise and James.
Edward, who is vice patron of the Commonwealth Games, shared a joke with former prime minister Theresa May as he entered during the men’s 1,500m freestyle heats.
William, Kate and Charlotte arrived shortly after and sat in front of the Wessex family.
Kate, dressed in a white blazer and trousers, embraced Edward, Sophie and their children before taking her seat next to Charlotte.
The Duchess was pointing and explaining things to her daughter, while William held one of the official programmes.
The royals were cheering and applauding alongside the crowd for England swimmer Luke Turley.
After rolling her eyes following a comment from her dad, Charlotte then cracked a smile as Turley’s heat came to a close.
Charlotte, Kate and William at the Sandwell Aquatics Centre
Jacob King
Princess Charlotte's antics stole the show
Chris Jackson
