The singer and her sister Ashlee celebrated their mother's 62nd birthday with a sweet Instagram post.
Simpson shared a photo of herself, her younger sister, Ashlee Simpson, and their mother smiling together while on an outing.
While all of the Simpson women are beautiful, Simpson's followers were amazed by how youthful Tina looked in the photo, with many saying that they initially thought she was another sister.
Simpson captioned the photo, "We are because She is… Thank you Mom for living 62 years of life to the very fullest. You inspire unwavering strength and determination with the purest of hearts. Hero status, indeed."
She went on, "We had a beautiful week celebrating our Mom- the natural born small and mighty! May God Bless you abundantly! Lovin’ you is one of life’s greatest treasures! 1.18.23."
While many wished Simpson's mother a happy birthday, others were stunned at her appearance, with one writing, "What the hell?! Did your mom find the fountain of youth?!?!"
"I think she’s aging backwards! Literally had to zoom in to make sure this was her! She looks like a 3rd sister! 😍☺️," said another.
Even more praised the family's good genes: "Wow you girls are inheriting some amazing genes from your beautiful mama."
Multiple people were so amazed that they weren't even sure that Tina was in the photo, with a follower commenting, "Wait their mom is in this pic?!?"
Along with raising Simpson and her sister, Tina co-founded Simpson's fashion line, The Jessica Simpson Collection, in 2005, and the two continue to work together to this day.