She worked for now-defunct chain Paris Texas' Wellington store, where she identified what she saw as a gap in the market for desirable New Zealand-made clothes that fitted New Zealand women for a reasonable price.
She had already made clothes for herself and friends and made a "pretty scary" move by offering her own clothes.
"I put together a collection by working nights after work, took it up to Auckland and pitched it to the owners and the buyers of Paris Texas," she said.
They liked what they saw and customers liked what they wore. She soon resigned to supply its stores.
"The response was awesome throughout New Zealand.
"It was definitely pretty hard work but it was my passion so it didn't really feel like work."
She said the hardest part was everyone asking the new business for cash up front, resulting in a few sleepless nights. But KILT has remained self-funding.
Opening her first boutique necessitated moving back into the family home and hiring her mother Helen to help as she started the retail arm of KILT in Palmerston North in 2003.
She distributed flyers for the opening but the cult of KILT was already alive and well - the shop doors opened to a queue.
In 2004 she moved to Napier's Ahuriri where she both designed and sold. Napier was chosen because she always liked visiting.
"It was definitely a good place to start and we went into Hastings St a couple of years after that."
The latest store was in Hamilton, chosen after KILT's Facebook page asked its customers where the greatest demand would be. The next will be Dunedin.
Precise streets are suggested by KILT fans, called Kilties. "Some even tell us when a good shop is vacant."
Customer feedback also helped with design decisions. The blouse that sales and marketing manager Lauren Hart wore when interviewed for this story started as a Facebook photo of the fabric, asking if it should be a blouse or a dress.
New boutiques are not the only growth path - KILT Bridesmaid Collection has launched with 12 styles for weddings.
KILT at Work has seen "some pretty cool businesses" achieve a uniformly stylish look.
New Zealand-made means costs are higher than China made.
Ms Williams said China did a good job making clothes "but New Zealand does it better".
Nonetheless China continues to bite down on the New Zealand clothing market. Cut, make and trim factories are steadily closing down, which was a problem until KILT recently opened its own factory near its Onekawa design centre in Napier.
"We love hearing of other New Zealand-made firms. We created New Zealand Made March - the whole month dedicated to celebrating New Zealand made and getting people to recognise that New Zealand makes good products."
More New Zealand companies enabled more production infrastructure "so it's a win-win for all". Contact with each store is made several times a day, including a Skyped "huddle" of managers in the mornings.
"It is a really good way to make you feel included and for everyone to bounce off each other," financial controller Victoria Walling said.
The chains trained share a daily picture of what they're wearing.
"We want to get inspired by what they are wearing so they send it out to everyone, so we can see different ways of wearing things," Ms Hart said.
Staff is united by the motivation for the establishment of KILT - nice well-priced New Zealand clothes for New Zealand women.
"The big thing is everyone's love of clothes and making women feel amazing," Ms Walling said.
"It's great when you hear about someone going into the store and finding a couple of beautiful dresses and going out happy and smiling."
Staff were used to receiving hugs, she said.
But it isn't always peace and harmony; family members have been known to fight over which will wear a particular style.
Ms Hart said there was no typical customer.
"KILT caters to so many age groups - a sweet spot would probably be between 25 and 45."
KILT doesn't do season collections because the pressure "could stem the creative flow of juices", Ms Williams said.
Instead designers aim for a new style every week, keeping a bank of styles up their tailored sleeves.
All clothing runs were limited, but if a style proved popular it was likely to be modified through a change such as a different fabric rather than elimination, she said.
"Some of the older lines have been an inspiration and we've tweaked them before bringing them back."
KILT also entered Westpac Hawke's Bay Chamber of Commerce Business Awards in 2011, winning the Small-to-Medium Business award.
"We learned from the judging process and set up an advisory board," Ms Williams said.
Staff in the Napier store were "a big part of the reason why we won the awards".
"Staff are such a massive part of the in-store experience."
The company employs 65 people for an equivalent of 34 fulltime staff.
Ms Hart said staff enjoyed contributing ideas for new styles, ideas always taken on board by the design team and Ms Williams.
"We don't try and keep up with trends, we just make what people want to wear," Ms Williams said.