The fashion designer took to Instagram on Monday -- one day after her actual birthday -- where she gushed about her 4-year-old daughter, Maxwell, and her 3-year-old son, Ace.
"36 and proud," Simpson captioned the heartwarming black-and-white snapshot of her kids running across their lawn.
It's sure to be a big year for the former recording artist, who has been teasing photos from inside the studio, laying down her first new tracks since 2010.
And as for her personal life, Simpson has never shied away from sharing photos of her precious kids, whom she shares with her husband, Eric Johnson. In fact, almost every pic on her Instagram is of them, and they can't help but steal our hearts every time.
Whether they are marveling at Ace's dinosaur themed birthday cake:
Or sitting by the edge of a pool, biting on toy fish:
Or rising a horse (despite looking kind of super nervous about the whole thing):
Or acting all sassy on a pier while drinking a milkshake:
Or hiding in a giant, decorative ceramic planter while wearing a fedora: