One woman from Canada was so affected by her death this week that she decided to pen an open letter to the fashion designer on Facebook, which described a heartwarming experience she had with her 5-year-old daughter at one of Spade’s stores.

The letter has gone viral, with thousands of people sharing it on social media.

“Dear Kate Spade,” wrote Heather Delaney.

“Almost four years ago, during a family vacation to Florida, I decided it was time to take my daughter, Elle (who was two months shy of six years old at the time), for her very first Kate Spade experience.”

Ms Delaney said she “couldn’t sleep” the night before because she was so excited.

“My husband would laugh as we laid there in the bed, me jumping with excitement, in anticipation of her and I getting matching bags the next morning,” the mother remembered. “This was a serious mamma dream come true.”

She had it all “pictured” in her head, according to the letter.

Ms Delaney’s daughter would get “the crossbody” — and she would get the full size.

“Brilliant,” the mum recalled telling herself.

But when the duo got to the store, plans apparently changed.

“We walk in. I show her the white [bags]. The black ones. The legendary stripped ones. Nope. Nope. Nope,” Ms Delaney explained, noting how none of the bags appealed to her daughter’s “style.”

“Then, she saw it. The first Kate Spade item that she would call hers.”

It was a pair of black, furry earmuffs.

“Her face would light up, and her eyes would go wide,” Ms Delaney said.

“She fell in love.”

The proud mother went on to say that she wished Spade could’ve seen her daughter that day and felt the love she helped provide for them.

“Kate, I’m sorry that we could not bottle that up for you,” she wrote.

“I’m sorry that we could not bottle up every grin, every laughter, every happy heart that walked through your stores. I’m sorry that we could not gather every smile that you put on a humans face, whether it was because they just found the most loveliest [sic] brooch for their wedding day, the most exquisite pair of earrings to wear on their Graduation Day, or even the most coziest [sic] pair of earmuffs to wear around Florida … And lay those smiles in your lap.”

In closing, Ms Delaney touched upon Spade’s mental health issues and described the guilt she felt over her death.

“I’m sorry that some are still scared by mental health, Kate. I’m sorry that some don’t understand it,” she wrote.

“I’m just so sorry you were sad, while you made so many others happy. So incredibly happy … I’m sorry, Kate, that we could not gift you the happiness that was felt in this six-year-old’s body that day … I kinda feel guilty now for feeling so much happiness that day, wondering now if you were perhaps sad that day.”

Ms Delaney finished the letter by praising Spade for being a “powerhouse” businesswoman, wife and mother — and provided an update on the earmuffs.

“You lived a life that others could only dream of,” she said.

“I hope that you are now at peace … and happy. I hope you are so, so incredibly happy … Oh, and if you’re wondering, Kate, no, I passed on the matching earmuffs. But I did get the most loveliest [sic] black purse to match the black in her earmuffs. Bless it.”

This article originally appeared on the New York Post and was republished with permission.

If you are experiencing mental health issues or suicidal feelings contact Lifeline on 13 11 14 or BeyondBlue 1300 224 636. If it is an emergency please call 000.