In the image, we were privy to a glimpse inside Blake and husband Ryan Reynolds's chic home, which based in the Pound Ridge neighbourhood of New York.
Wooden floors, stone walls, a lantern and a fairy light installation made for some serious fairytale energy, all the more apt next to Blake's eye-catching green gown.
Later, Blake again took to her Instagram stories to share a snap from inside her wardrobe (yes, it was decked out with Louboutin heels). There, she revealed another birthday surprise, a Louis Vuitton handbag.
Comically, the actor pointed out the fact that yes, she wasn't wearing pants in the image. Ever relatable, she affirmed that simply throwing a towel on was just as appropriate for the day's events at home.
"Shout out to my fellow pantless friends running around," she quipped.
Blake and husband Ryan Reynolds share three children, James, six, Inez, four, and Betty who is almost two.
While the pair like to keep their children largely out of the public eye, Ryan has previously said of his girls: "They’re the best. They’re my buddies. I love it."
Blake has also been candid about their growing family: "I mean, we have so many children. It’s pretty crazy. We’re outnumbered, and it’s a lot. It’s like going from two to 3,000."