08/30/2011 at 05:00 PM EDT
It's been just seven weeks since Kate Hudson gave birth
to her son Bingham Hawn
, but the actress appears to have snapped right back into shape.
Hudson, 32, along with her fiancé
– and Bingham's dad – Muse frontman Matt Bellamy, took a dip in her hotel pool in the South of France Tuesday.
The actress looked relaxed as she rocked a sheer white bikini while playing in the water with Bellamy and her elder son, Ryder, 7½, with Black Crowes frontman Chris Robinson. While the three splashed around in the water, Bingham stayed on the sidelines, according to an onlooker.
The family had traveled down to Antibes after spending time in the U.K., where Muse played a few summer concert dates.