Her current job: Mr. Lagerfeld referred to Ms. Viard as both his right and left hand. As soon as he completed a sketch, her work began. She oversaw six collections a year and also served as a translator of Mr. Lagerfeld’s vision. She spent time with suppliers and the heads of seven ateliers and assessed what new or archival techniques best corresponded to Mr. Lagerfeld’s ideas. Her involvement extended to approving the model casting and inspecting each detail backstage.

“I always see her concentrated and smiling,” said Mr. Prigent, who added that she seemed “absolutely loyal to Karl.” And, he said, “I have never heard her complain about the crazy pace of the collections at Chanel.”

Her rapport with Mr. Lagerfeld: Ms. Viard has said that Mr. Lagerfeld was the only person she addressed with the formal French “vous,” and that she enjoyed doing so. In the Grazia profile, she said: “My role with him consists of making sure he feels good. Over the years, there have been tiring moments, things unspoken; but overall, always, respect and kindness. We communicate each morning by text.”

But she was never his yes person. “When I have something to say, I tell him,” she told Madame Figaro in 2011.

Her style: Ms. Viard’s signature is her fringe: a shelf of 1960s-era bangs that graze her smoky eyes and balance her shoulder-length slept-on waves. She is often in a Lagerfeld-like uniform of rocker-chic black jackets, skinny black jeans and vintage T-shirts. Think Coco Chanel crossed with Patti Smith.