The Duchess of Sussex has long demonstrated her capacity to influence consumer behaviour

A sustainable fashion brand’s festive party dress has completely sold out after four-year-old Princess Lilibet was photographed wearing it during a Thanksgiving charity visit.

The young royal accompanied her parents, Prince Harry and Meghan Markle, and brother Prince Archie to volunteer at a Los Angeles community kitchen this week.

Royal enthusiasts have quickly coined the phenomenon “The Lilibet Effect”, drawing parallels with her mother’s well-documented ability to drive retail sales.

The red tartan frock from Hope & Henry sparked immediate consumer interest, with fans noting the youngster’s emerging influence on children’s fashion trends.

‘Princess Lilibet effect’ sees £38 dress sell out instantly | INSTAGRAM: @MEGHAN / HOPE & HENRY

The Hope & Henry “Taffeta Party” dress featured black bow detailing and ruffled short sleeves, originally priced at £38 but reduced to £26 at the time of purchase.

During the charitable outing, the youngest Sussex child’s distinctive bright red locks were styled in a neat plait beneath a hat.

Whilst the family kept their daughter’s face private in the photographs, her vibrant auburn hair – matching her father’s colouring – was clearly visible.

The sustainable brand’s website quickly experienced unprecedented demand following the images’ release, with the tartan design becoming unavailable across their primary retail channels within

Princess Lilibet’s dress is no longer in stock | HOPE & HENRY

The Duchess of Sussex has long demonstrated her capacity to influence consumer behaviour, with items she wears experiencing rapid sales increases.

In 2018, a Strathberry handbag she carried during an official engagement sold out just 11 minutes after photographs emerged.

Since departing from royal duties in 2020, Meghan has strategically invested in multiple fashion brands, including Cesta Collective, whose handbags she has worn publicly on several occasions.

Her wardrobe choices consistently generate significant retail impact, mirroring the Princess of Wales’s ability to drive immediate sellouts.

Princess Lilibet’s dress is described as a ‘taffeta party’ garment | HOPE & HENRY

Social media users were swift to highlight the generational fashion influence, with one commenting: “Like mother like daughter.”

Another enthusiast declared: “Welcome to the Lili Diana effect y’all!”

A third supporter added: “If I had a daughter I’d buy it too. Adorable!!”

Although unavailable through Hope & Henry’s main platform, the dress remains accessible via Amazon and other third-party retailers.

Archie and Lilibet join Prince Harry and Meghan Markle to volunteer in Los Angeles. |INSTAGRAM: @MEGHAN

Alternative colourways appear to maintain stock levels at present.

Princess Charlotte similarly generates retail rushes, with a £39 Rachel Riley dress selling out within 24 hours following her 2022 Commonwealth Games appearance.

The 10-year-old’s preference for Spanish labels and Papouelli footwear has driven international demand for these brands.