The singer has three kids with her husband, Eric Johnson.
Jessica Simpson's kids are growing up! The 40-year-old singer took to Instagram over the weekend to pay tribute to her oldest child, Maxwell, who turned nine on May 1. Simpson shares Maxwell, as well as Ace, 7, and Birdie, 2, with her husband, Eric Johnson.
In honor of Maxwell's big day, Simpson shared a photo of herself, Johnson, and their two oldest kids posing with a horse. The pic was of note because, in Simpson's Amazon Original Stories essay, Take the Lead, she opened up about how Maxwell helped her conquer her fear of horses.
In the same essay, which followed the release of Simpson's 2020 memoir, Open Book, the singer revealed that Maxwell now wears the iconic boots she sported in her 2005 flick, The Dukes of Hazzard.
"Maxwell, my best friend and first born, turned nine yesterday, May 1," Simpson began her lengthy caption. "If any of you have read my memoir, OPEN BOOK, or my Amazon essay, TAKE THE LEAD, then you have a sense of my forever baby girl (even though she will be taller than me in about six months and shares my shoe size)."
Simpson continued her loving post by describing her first born as "prayerful, nurturing, intuitive beyond belief, hilarious, honest, a lover of horses and every animal on the planet, empathetic, wise beyond her years, thoughtful, strong, beautiful, hardworking, creative and observant (which makes her one of the most epic impersonators to make anyone laugh)."
"She is a prolific writer of poem and songs, and she listens and trusts herself with confidence I admire," she continued. "The energy in a room shifts when she enters. Yes, she is the most beautiful I ever did see, but it is the effortless way she holds her power that is unlike anything I’ve ever seen."
Simpson noted that her daughter's "inquisitive mind strengthens mine," adding that Maxwell's "heart holds space for everyone and everything."
"When I think about her I can’t help but smile with all that I have, a happy smile is always inspired by her, the possessor of the most genuine, pretty, sometimes cheeky but always the purest of smiles ever to grin," she continued. "My favorite hands to have and hold in prayer or just in life are hers, always my daughter. She loves you enough to be the person you have always wanted to be."
The proud mom ended her birthday tribute by writing that she's "constantly in awe of her resilience and grace, it is amazing indeed."
"I love her beyond measure," she concluded. "Happy belated (to Instagram) birthday Maxi!"
When ET spoke to Simpson in March, she praised Maxwell, even likening the tot to someone else who's important in her life.
"My oldest daughter is so much like my sister," Simpson told ET of 36-year-old Ashlee Simpson. "The part of my sister that I’ve always envied is she is just unapologetically authentic... It's pretty awesome. I love raising somebody like my sister because... I just need to be cool enough for my daughter and my sister."