"As I struggled in bed, my symptoms got worse," she said, recalling that morning. "I was gasping for air ... unable to speak."
Now she wants to put it behind her.
"Fortunately, my stroke was really minor, and once I was able to get on with the job, I didn't really want to know anything else about what might have caused it," she told The Associated Press in an interview. "About 30 percent of young people who have strokes, they never determine the cause."
Kennedy-Sim, whose best World Cup finish is fifth place (twice in 2012), has been ranked as high as 11th in ski-cross, but dropped to 23rd after a self-described "appalling" 2012-13 season which included a concussion from a crash in training at a test event in Sochi.
She has high hopes for a return to the Black Sea resort in Russia that has been transformed to host the Olympics, particularly after her intensive, five-week training camp in New Zealand.
"It was really productive," Kennedy-Sim said, "and gave me some confidence."
It's crucial to have a healthy dose of confidence, and bravado, in a sport that has been described by some as "NASCAR on skis."
On March 10, 2012, Canadian Nik Zoricic crashed hard through safety nets, suffered severe head injuries and died in Grindelwald, Switzerland during a World Cup event. It brought less than ideal publicity to the sport which only made its Olympic debut in Vancouver in 2010.
At Sochi, there'll be 32 finalists in both men and women's events. They'll race down the hill in groups of four, bouncing over natural and sometime very unnatural terrain.
Kennedy-Sim, who knew Zoricic, says the ski-cross fraternity is a "very tight group" of about 120 athletes who socialize on and off the slopes. She thinks the "NASCAR on skis" reference is unfair, and doesn't agree with it at all.
"It was really unfortunate what happened to," Zoricic , she said. "But it's not the first time it's happened in sport, and it won't be the last."
Kennedy-Sim said the ski-crossers have formed an "alliance" to make sure that competition sites are not dangerous and "that our safety is not compromised." They gave the planned Sochi course the thumbs-up in February during the test event.
Ski-cross started appealing to Kennedy-Sim when she was barely out of her teens, mainly because she didn't like the way Alpine skiers competed against the clock rather than side-by-side against other athletes.
No surprise then, Kennedy-Sim says she's "weak" in qualifying runs when ski-crossers do race against the clock to determine seedings for preferred start gates and heats against weaker opponents in preliminary rounds. She'll look forward to getting that part of the competition out of the way and speeding down the hill with three others.
She'll overcome the odds just by making it to the starting gate, and will no doubt raise some awareness of strokes, which can impact on men or women at any age. She was lucky her husband, former Olympian Ben Sim, realized quickly when Kennedy-Sim needed emergency medical treatment.
"Sami was fortunate her husband recognized the signs of stroke," said Dr. Erin Lalor, chief executive officer of Australia's National Stroke Foundation. "Fortunate she was close by a hospital, fortunate she now has a great doctor looking after her and access to a specialist rehabilitation team."
As she looks forward to Sochi, Kennedy-Sim is reminded of the motto she has featured prominently on her own website, one she stuck on her wall in her bedroom when she began Alpine skiing.
And one which, following recovery, seems to be even more appropriate: "Passion + Persistence = Performance."
"It's always stayed with me," she said.
No one is more aware of that than Kennedy-Sim's husband. He knows the rigors of training following his cross-country ski career, which included the 2010 Vancouver Olympics and five world championships.
"As scary as it was for Sami to have that setback, she couldn't just sit there," Ben Sim said. "Persistence is the biggest thing. She knows she has to keep training hard and not only make it to Sochi, but hopefully do well there."