Faith, 3, broke her leg in the crash and had her cast taken off on Thursday. Phoenix, known by his family as Phee, had a broken pelvis, two broken femurs and a fractured arm which left him in casts covering about 75 per cent of his body.
His casts are also off but the 4-year-old is now learning how to walk again.
"He has had a couple of knocks," Mr Ruddell said.
"But he will get back up and try again. He is determined."
On Monday, the pair would be heading back to preschool , a move that Mr Ruddell said they were ready for.
"I've based my decision on them. We took them down to school and their reaction ... They just ran straight in and got stuck in," he said.
"Phee went straight in and Faith just got into the paints."
Mr Ruddell remains convinced the children knew their mother had died soon after the crash happened.
"I think they knew but just didn't understand ... We've had that conversation and it was really challenging but they are in a good space and will tell me how they feel and what's going on."
A memory box has been put together with newspaper clippings about the crash and sympathy cards and Mr Ruddell hoped the children would be able to go through it when they were ready to help them understand what happened.
Mr Ruddell and the children were living with his parents in The Lakes, and to help settle Phoenix and Faith in they were converting the garage into a playroom.
"It will be nice for them to have their own space."
He said the support the family had received was "phenomenal".
"We have just had a constant stream of messages and offers of support."
More than $11,000 had been raised for Faith and Phoenix via Givealittle and Mr Ruddell planned to use some of these funds towards taking the children on a trip.
"Most of it will be set aside for the kids but I'm thinking when everything is done and dusted and blown over, I'd like to take them to the snow for a week. Neither of them have been to the snow so it would be a cool little treat."
