"Eighth October, 2019, was the [worst] day of my life.''
She included a tearful icon emoji next to her message and a simple red heart.
The Givealittle page - titled "our precious boy Nekko Paul" - features a photo of a happy little boy either in mid-laugh or shout.
He is sporting a fluffy white beanie with flaps covering his ears.
"Nekko had the brightest future ahead of him. Unfortunately... his life was taken too soon by a tragic accident," family friend Abbey Marshall wrote.
"Nekko had a beautiful smile and personality that was one in a million.
"Cheeky, bubbly and full of energy - he could light up any room he walked in to."
Marshall said Nekko would always be in their hearts and minds and they would cherish the memories they made with him forever.
"You will be the brightest star in the sky. We all love you and miss you so much."
Police in the area are still working to piece together exactly what happened before it is thought Nekko fell overboard. It is understood he was with his mum's partner at the time.
Police said late on Tuesday afternoon that they recovered the boy's body just over seven hours after he was reported missing.
The Police Dive Squad pulled the lifeless boy from the water about 1.45pm and confirmed he was the child reported missing.
An autopsy was due to take place yesterday.