"She should gradually come back. She did smile yesterday though. It was really lovely, it was so good," she said.
"It's still very early days yet. We're just taking each day as it comes.
"We have got a lot of support, and family on both sides, with her partner. And so we share it.
"It's something you just do not expect to happen to yourselves, but you just have to hang on in there."
A Christchurch Hospital today said Amelia's condition remains critical.
Barbara said she received a phone call about 11.15pm from Amelia's boyfriend, who said: "We've been attacked. Amelia's come off worse than me."
She said the attack near Park Tce and Salisbury St "took [the couple] by surprise".
"They don't know why they were attacked - [the attackers] took Amelia's hat to start and maybe something was said between them? But no one deserves something like this to happen to them."
Detective Sergeant Colin Baillie today said the investigation is ongoing.
A number of people have been spoken to, he said, but police are still appealing for witnesses to the attack to come forward.
"Further information is not available at this stage as it is subject to investigation," he said.
Witnesses or anyone with information should contact Christchurch Police on 03 363 7400 or anonymously via Crimestoppers on 0800 555 111.
