Day four in hospital for three brave survivors.

The tragedy claimed the lives of their parents, Jake Day, 28, and Cindy Braddock, 25, just minutes out from their home town.

"We're just taking it minute by minute at the moment," relative Michael Read said outside Perth Children's Hospital.

"They're doing great. We've just brought them down here for lunch earlier today ... yeah, they're little champions."

Today the family thanking a truck driver who pulled over to comfort family members who found the tragic scene just metres from the road.

"The family is just grateful for him being there. Unfortunately we don't know his name but we just wanted to say a big thank you.

"It really meant a lot to not only myself but to the entire family."

Also, the family today thanking the WA community who have rallied behind the three young children with a crowd-funding campaign raising close to $100,000.

"It's gonna be a real help to the kids' upbringing and again I just want to thank everybody for chipping in and helping out where they could," Read said.

Family members are still working through how the children will be cared for when they're discharged from hospital, which is expected to be any day now.

"We're handling it the best we can. We're all hurting in different ways but we're just putting the kids first at the moment."