The sweet seven-year-old could be seen giving her dad a thumbs-up at one point, and appeared thoroughly engaged as she watched the swimming events poolside.
However, sights like this might be less common at the next Commonwealth Games.
WATCH: Duchess Kate and Princess Charlotte share a sweet mother-daughter moment
The simple reason for that is that the next games will be held in Australia, which will make it much harder for the royals to commute!
They also won't take place for another four years, after which time Louise is likely to have a job and James may be studying or working.
Prince William and his daughter arrived by helicopter
Britain previously hosted the games in 2014 and before that, in 2002, 1986, and 1970, which was the first time The Queen attended.
Although Charlotte looked pleased to be representing her great-grandmother at the event, she did appear to be distinctly unimpressed with her dad at one point in the proceedings!
As Prince William smiled widely while posing for a selfie with some fellow spectators, the royal youngster could be seen standing to the side and shooting a doubtful glance at her father.
Princess Charlotte enjoyed the swimming alongside her parents
The Cambridges sat just in front of the Earl of Wessex, who is Vice-Patron of the Commonwealth Games Federation, his wife Sophie, and their children, and the Cambridges fondly greeted their relatives with hugs on arrival at the venue.
Charlotte had previously delighted the public by starring in a social media video with William on Sunday which saw the duo wish the Lionesses well ahead of their 2-1 victory over Germany in the Euros final.
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