She said he was sat in her kitchen with his daughter, Meadow, as he was talking about plans to pick out a Christmas tree and decorate it together.
"We were having this good conversation, and he'd forgotten about an event he had," says Cheryl.
"He got a text and said, 'Oh my gosh, I'm supposed to be somewhere!'"
On November 30 2013, the 40-year old actor left for his organisation's charity car show event.
Several hours later, the actor left the event in a Porsche sports car driven by his friend Roger Rodas - who also died - when the vehicle crashed in California.
The Los Angeles County Sheriff's department said its deputies found a car engulfed in flames when they responded to a report of a collision. Both were pronounced dead at the scene.
"I think so many people think, 'Oh, he was just a movie star, who was killed in a car accident,'" says Cheryl.
"But there was so much more to him. That was just a piece of who he was. He was such an amazing man," she continued.
Almost five years after his death, footage of a young Paul Walker has been made into a TV documentary about the Fast & Furious star. I Am Paul Walker is scheduled to be released later this month.
It also features interviews with his family and colleagues such as director Wayne Kramer and fellow Furious co-star Tyrese Gibson.
"If you loved him the way we did, you would say 'Well, why him and not us?'" says Gibson.
His mother, Cheryl, says: "I've gotten letters from people all over the world who said he made a difference in their lives."
"That is such a blessing. He's never forgotten."