A heartbroken mother has to bury her five-year-old son after he was killed alongside his father and another woman in a crash on Easter Sunday.

Achillies Aiken and his father swerved off Princes Highway 13kms south of Ulladulla at 4:30 am and smashed into a tree.

The little boy and his father died at the scene as well as the car's female driver, with an adult male passenger surviving with serious injuries.

A fundraiser has been set up to help raise money for Achillies' memorial service on Monday and paid tribute to the car-loving five-year-old whose "little life had just begun".

"No mother should have to bury her child," the GoFundMe's organiser Karen Gough said on the page.

"We all think little children are special but he truly was. He was full of spirit with a love of his cars like you've never seen."

The page has raised almost $1,500 towards its $5,000 goal.