TORONTO -- A 10-year-old girl and her 4-year-old brother who died after being struck by a vehicle in Vaughan, Ont. on Sunday are being remembered as confident and fearless children who "are loved beyond words" and "missed beyond measure" by their family.

A message paying tribute to the siblings was posted to the fundraising page that has been set up in their memory.

The family of the siblings is encouraging people to donate to the SickKids Foundation in lieu of flowers. The fundraising page identified the children as Anaya and Jax.

York Regional Police said the family consented to the use of the photo and information on the page.

Anaya is being remembered as an athletic girl who was “full of courage” and whose smile “brightened up the world.”

"She was an amazing big sister who took care of all those around her," a post on the fundraiser website read. "She was the best of both worlds, loving art as much as science and technology. She was unbelievably strong and could do more pull-ups than all of her older cousins....but NEVER at the expense of her hair and nails."

"She knew who she was and wasn't afraid to show it. Our beautiful bold Nanu will be deeply missed."

Her brother Jax was described as a free-spirited, vibrant and energetic young boy who loved wrestling and wanted to grow up to be a Ninja Warrior.

"He was a fearless little boy who was always ready for his next adventure," the post read. "An animal lover who loved to roar like his favourite dinosaur. He would melt your heart with his sly smile and endless hugs and kisses."

"Our little Jaxie will live in our hearts forever."

Anaya and Jax were playing in the driveway of their home near Dufferin Street, north of Teston Road, at around noon on Sunday, along with a neighbour fixing a bike when a black Mercedes sedan struck them.

The siblings sustained critical injuries and were rushed to hospital, where they later died. The neighbour sustained non-life-threatening injuries.

The tragedy has shaken the quiet, residential street where the family lives. There is a makeshift memorial outside the siblings’ home where friends and neighbours have dropped by to pay their respects.

On Tuesday, the family issued a statement through police, saying they are traumatized by the incident.

"The past days have been extremely difficult for our family. We appreciate the prayers and thoughts of all those grieving with us," the statement read.

The driver of the Mercedes, a 16-year-old Richmond Hill resident, was arrested after the collision and is now facing six charges, including two counts of dangerous operation causing death and two counts of criminal negligence causing death. The driver cannot be named under the terms of the Youth Criminal Justice Act.

As of 5:30 p.m. Thursday, the fundraiser has raised more than $51,000 for the SickKids Foundation in memory of the siblings.