The jolly family party included her husband Prince Albert, his sister Stephanie and her daughters Pauline, 17, and Camille, 13.
Stephanie's girls seem perfectly at home in the royal spotlight – Pauline particularly has been looking more grown up and elegant in recent months.
The 17-year-old, from her mother's marriage to her former bodyguard Daniel Ducruet, has made her family proud by competing on the junior diving circuit.
She also clearly takes after her gorgeous cousin Charlotte Casiraghi, who is Princess Caroline's daughter.
Seeing the children of her sisters-in-law growing up, Charlene, 33, must be looking forward starting her own family.
And onlookers may have been wondering if that elegant black cape was concealing a happy secret.
Admirers will note that the former Olympic swimmer has steered clear of the form-fitting dresses she often wears to which show off her statuesque figure, in favour of looser garments.
But there's been no official announcement forthcoming from the Monaco royal palace as of yet.
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