Tafua had a six-hour operation to relieve pressure and attempt to fuse his vertebrae.
His father Oliva was in Samoa at the time and was due to arrive today with Tafua's sister Helen Karati-Tafua.
His mother Akesa, who arrived with his brother Lalovi from Wellington the morning after the accident, said it was good to see her son smiling.
"He's started eating some and is working hard to move his hands ... not the legs at the moment but ... yeah."
She said news of the accident had been difficult.
"I didn't know what to do...all I wanted to do is come and share his pain."
It was an emotional meeting with team management when she arrived.
"We've just been crossing our hands, everybody, and praying hard out," she said.
Mrs Tafua planned to stay in Australia for at least a month.
Tafua's team mate Ben Matwijow and the New Zealander's girlfriend Katie have remained at his bedside.
In spite of his condition he had been in good spirits, said Matwijow - "typical Seti, he's always good for a laugh".
The ongoing effects of the accident remained unknown, said O'Donnell.
Tafua still has no movement in his lower half, and "the prognosis of that is not very good," O'Donnell said.
"This is going to be a very, very slow process. He may be in Royal North Shore for months. They (the doctors) haven't given too much away on that but ... us and his family [have] to realise there is a very good chance he unfortunately may be in a wheelchair for the rest of his life."
The club has organised two fundraising days for Tafua and Northern Suburbs' game against Eastern Suburbs at Woollahra next weekend would be televised - "we really want to call it the Seti Tafua day," Mr O'Donnell.
Tafua previously played for the Wellington Under 20s team.