Meet Ruby Davis: the younger sister of Roxy Jacenko you've probably never heard of.

She’s spoken at length publicly about the close bond she shares with her mum but the relationship between Roxy Jacenko and her younger sister Ruby Davis isn’t something we hear much about.

Sharing images from her adventures in Los Angeles, London and St Tropez all in the last week, Davis’ Instagram is world away from Roxy’s, who recently underwent surgery for breast cancer, is busy running her PR empire and raising her two young children alone while husband Oliver Curtis serves his prison sentence for insider trading.

“Had such an amazing time in St Tropez,” Davis wrote in one post, continuing, “En route to Barcelona.” In another image, the digital entrepreneur wrote, “New friends & lots of adventure!”

Ruby on holiday last week. Source: Ruby Davis Instagram. 

It was widely reported in 2008 that Ruby punched Roxy in the nose while out at a popular Kings Cross club. While police took out an interim Apprehended Violence Order against Ruby at the time of the assault it was later revoked and dismissed.

Despite this she did attend her sister's high profile Sydney wedding in 2012.

But if there's one thing the sisters have in common, it's their love of luxury cars.

Relocating to Los Angeles in recent years, Davis launched ChickDriven, a female-focussed auto website, in November 2015.

"Chick Driven was created in response to the daily negative experiences of thousands of women with automobiles," Davis told Sexee Mag, explaining the site was launched in a bid to "empower women navigating the car market by providing them with helpful resources as a trustworthy voice."

Listen: Rosie Waterland and Laura Brodnik discuss Roxy on The Binge podcast: