Jennifer Neville-Lake of Brampton, Ontario, uploaded a video of her children Daniel, 9, Harry 5, and Milly 2, rehearsing a dance they planned to perform for Neville-Lake and her husband Ed on their 10th wedding anniversary.
The video, posted on Facebook on Oct. 17, has more than 600,000 views.
The children died last month in a car crash.
"I want to show the joy of my kids too and this is the only video I have of them just being themselves and just being happy," Neville-Lake told ABC News today. "That was just them. That’s why I wanted to post that to share in the joy of my children.
"It's surprising but heartwarming to know that we are not alone," she added. "There are people crying with us."
Neville-Lake shared intimate details about the children with ABC News.
"Harry was a bilateral partial hand amputee, meaning he had non-functional thumbs," Neville-Lake added. "Harry had a lot of compilations, but he was very, very happy. He loved music. He had to do everything that Daniel, his older brother, would do. Milly was real feisty and mischievous. She was a daddy's girl."
Neville-Lake had sent the kids to visit their grandparents, who lived 45 minutes away. On Sept. 27, the day her parents were bringing the kids back home, Neville-Lake said she received a frightening phone call from a friend who heard there was a serious car accident involving three children.
"[My parents] were running late and I was getting annoyed," Neville-Lake said. "But when five o'clock hit I was like 'This is really late for them.' I tried calling their phones and they didn’t answer me. I flipped on the news and I saw the crash and I said 'That’s my van.'"
Neville-Lake said she had her license plate number sent to police, who then recommended she come in to see them.
When Neville-Lake and her husband Ed arrived, they were informed that their eldest son Daniel died shortly after the crash at Etobicoke General Hospital in Toronto.
Neville-Lake's father, Gary Neville, also died in the accident.
Neville-Lake's mother, Neriza Neville, and children's great-grandmother, Josefina Frias, who were also in the vehicle, were the sole survivors.
Harry and Milly were airlifted to The Hospital for Sick Children in Toronto but Neville-Lake said both kids soon lost all brain activity and soon passed away after being on life support.
"I remember saying to the doctor, 'All of my children? All of my children are gone? This cant be true,'" she said. "Our lives are pretty much over because our whole family has been taken. There's always talk about rebuilding, but out of our little Neville-Lake family, now there's just Ed and I.
"It's really, really hard to believe because in a way it feels like they're just away with my dad because he did have them for long weekends," Neville-Lake added. "I don’t get kisses from them in the morning anymore. When I'd leave for work, they'd hug and kiss me and wave from the porch. Whenever I'd come home from work they'd run, and hug and kiss me."
She added: "I'm sitting right now in Harry's bed with Milly's comforter and these are the pieces I have now. It's hard to live through, but the sense of support and solidarity is so comforting. I just hope my kids are not forgotten -- that’s my biggest fear."