The 32-year-old jetted back to the UK after launching her business in LA to spend time with her little one – but her husband Paul Knightley was nowhere to be seen.
The former Towie star kicked off the day with a fun-filled celebration in their hotel – featuring an incredible balloon display and a stunning floral pink cake.
They then attended the shopDisney’s exclusive VIP event at The Disney Store on London’s famous Oxford Street – where Rosie was showered with gifts including a pair of Frozen themed cowboy boots.
The perfect day was rounded off with a trip to luxurious eatery Zuma, where she was presented with an incredible dessert platter.
Marking her daughter’s special day, Sam wrote: “To my lovely Rosie, happy 6th birthday, my darling.
“You are not only my daughter but also my best friend, my number one girl, and my everything. You have a wonderful sense of humor, kindness, intelligence, and a touch of sassiness. I am incredibly proud of you, my princess.
“Let’s make this weekend the most amazing celebration ever.”
Sam and her partner Paul are parents to Paul, Rosie and Edward.
The pair have been together for 10 years but have never tied the knot.
In recent months Sam has been very busy working on her business Revive Collagen.
She flew to America with her business partner last week to launch it over there and announce Kim Kardashian’s hair dresser Chris Appleton as her new ambassador.
Sam has made no secret of her wish to live in LA and previously planned to move her family there for three months – which caused upset with her sister Billie.