"That's when we found out," she said.
She could see the boy's body on the rocks from a distance at North Piha, and said it looked like he might have fallen.
Kelsey-Ann had seen a woman on the beach during the search who she believed to be the boy's mother.
"She just looked devastated, had her head in her hands."
Kelsey-Ann said she felt "horrible" when they discovered what happened to the boy.
"I'm an early childhood teacher, it really hit home. I felt so sorry for his parents, it must feel horrible, I can't imagine it.
Police are yet to release the child's name, as they are still informing family of the death. They have confirmed the child did not drown.