The international fashion scene is studded with successful sibling couplings: the Miller sisters, Sienna and Savannah, created the Twenty8Twelve label; Penelope and Monica Cruz produced a Spanish-inspired line for Mango, and London Fashion Week's new it girls are the Felders, Daniela and Annette, from Germany.
The Kardashian trio of Khloe, Kim and Kourtney had their DASH boutiques before they became a TV phenomenon, while the best example of sisters morphing from TV to fashion are the Olsen twins.
Mary-Kate and Ashley defied their critics and built not just one desirable brand – The Row – but added a second, Elizabeth and James, named after their youngest siblings.
The field is wide open here for sisters to carve a niche for themselves, just as the Tucker sisters did at Costume on Dublin's Castle Market in the 1990s. And the Ryan sisters attracted fashion fans – including Beyonce – when they opened Chica at Dublin's Westbury Mall.
KDK is the latest family fashion brand to attract attention, spearheaded by sisters Keira and Dairine Kennedy. Both have business degrees, a Masters in marketing from Smurfit and an aching for creativity, art and entrepreneurship.
'Luxury for everyday life' is the design ethos of their brand, and their 100pc cashmere scarves for men and women (from €199) are boosting traffic to the girls' KDK.ie website as well as to boutiques in the know, such as Costume and Khan.
The sisters demonstrated enterprising verve early on and they laugh as they recall how, as kids, they made homemade lemonade and sold it to GAA fans on their way to Pairc Ui Chaoimh.
Nowadays, they are confirmed rugby fans. Keira is Leinster Rugby commercial and marketing manager and Dairine is a True Blue fan – well, she is married to Leinster captain Leo Cullen.
Childhood exploits – making perfume from rose petals – was a clue to their strand of creative DNA, and their brand KDK was born after Keira went on honeymoon to India and came back with luxurious, paper-light, 100pc cashmere scarves.
Keira had the sense to buy them as presents for friends. The constant, positive feedback resonated with the Kennedys, and they placed their first order for digital-printed cashmere scarves a year ago.
"We were brainstorming things to do as sisters; what business could we get into together and we were really keen to make it happen," explains Dairine, who works at Google as an online management and sales specialist.
"For me, it was always print," says Keira, "and I look at prints and think, 'That would be beautiful to wear'. I love photography and am constantly taking photos. That was the basis of the scarf images."
The designs range from trees in Connemara to plants screen-printed on both sides of each scarf.
Role demarcation at KDK has been "easy", according to the sisters, "because we are clearly different. I am more 'let's wait until it's finished and we are sure', and Dairine is more 'we just need to do it now'," says Keira, who is four years older.
For spring/summer 2013, their scarf collection has a theme of birds and secret gardens in shades of pinks and green. For autumn/winter 2013, the collection is nature-inspired, with jungle prints and wild animals in colours such as tawny brown, slate grey and midnight blue.
There are further rugby resonances as Aoife Cogan, wife of Ireland and Leinster player Gordon D'Arcy, was the model for their photoshoot with Barry McCall. And when Dairine's husband Leo dropped in to say hi, he found himself in front of the lens with the sisters, wearing one of their two men's designs.