In an Instagram post, the fashion designer shared a mirror selfie of herself and her 11-year-old daughter, both dressed in Victoria Beckham gowns.
The image features the mother-daughter duo standing alongside each other while holding hands as they pose in what appears to be a dressing room. Another snapshot in the post includes a photo of model Isabela Rangel Grutman and Beckham, 48, in the latter's Spring/Summer 2023 collection.
The Spice Girls alum called Harper "my number one" Victoria Beckham "muse" in the caption.
"Mummy loved creating this dress for you 💙," she wrote, adding, "I love seeing my new collection on you @IsabelaGrutman!! You look incredible! Kisses xx VB."
In addition to Harper, Beckham also shares sons Brooklyn, 23, Romeo, 20, and Cruz, 17, with husband and soccer star David Beckham, whom she married in July 1999.
In October, Beckham's family members came together to show their support at her first ever Paris Fashion Week show.
Sitting in the front row, the group was joined by British Vogue Editor-in-Chief Edward Enninful and Vogue Editor-in-Chief Anna Wintour.
Brooklyn Beckham's wife Nicola Peltz Beckham, as well as Victoria Beckham's parents, her sister and nieces were also united in the family affair, where the designer showcased her Spring/Summer 2023 ready-to-wear collection.
The designer later shared her appreciation for the support in an Instagram post featuring a series of pictures of her family members at the show, writing in the caption, "I love you all so much x."
Congratulating his wife on her success of her titular fashion brand, which she first launched back in 2008, David Beckham, 47, posted a photo of Victoria Beckham from the show and penned a loving note in his Instagram caption.
"PARIS BABY 💙🤍❤️ Today we celebrate YOU @victoriabeckham," he wrote. "You have worked so hard to get to this moment so enjoy it but remember it's only the beginning for you & team VB we are so proud of you ❤️."