Family members say the mother of seven wasn't feeling herself when her vehicle plunged into Lake Gladman in Wyndham Vale on Wednesday with her four youngest children on board.
Akon Guode's five-year-old daughter, Awel, was pulled out of the water critically injured but Bol, one, his four-year-old sister Anger and her twin brother Maudit, died.
Their father Joseph Manyang visited Awel in hospital on Friday and says she's getting better.
Mr Manyang was worried her memory might have been impacted so he asked Awel if she recognised him.
"She said, `Yes, you are Daddy'," he told the ABC. Mr Manyang is devastated by the deaths but does not believe Ms Guode deliberately drove into the water. He said she only remembers hearing her children's cries.
"That's what she said to me. When she was driving, she feel dizzy and then she lose control and then she didn't remember anything until she fall in the water," Mr Manyang told Fairfax media.
He said there were untruths circulating but people should wait for the ongoing police investigation to reveal the truth.
"What I believe is she can't do that (harm the children) ... because she loved the kids," he told SBS Radio.
Ms Guode, 35, returned to her family late on Thursday night after being held in custody and questioned over the tragedy.
She is understood to be heartbroken and is reportedly staying with an aunt in Morwell in eastern Victoria.
South Sudanese community members say she came to Australia as a refugee widow with three children after her first husband died.
They described her as a good mother who would do anything for her children. Ms Guode's daughter Akoi Chabiet, 19, said their mother was a wonderful person and would never do anything to hurt her children. "My mother is a very good lady.
She would never deliberately do this," Ms Chabiet told Fairfax on Friday.
A makeshift memorial near the lake continues to grow, with many leaving messages of love, flowers and soft toys.
A candlelight vigil in memory of the children is planned for the weekend. It is not yet known when a funeral will be held.
