Police have interviewed a man believed to have caused her injury.
Ms Rayner's father Gary Rayner said he would not comment on the outcome.
He said he has engaged a lawyer.
"It wasn't going anywhere so we have got a lawyer to follow up just what is happening," he said.
Mr Rayner said Amelia was recovering well and was soon thinking about returning to work.
He said her voice is coming back but she is still "a bit jumpy".
"The physical stuff is the easy part, the mental part is difficult to move past," he said.
It is alleged Ms Rayner and her boyfriend were leaving the festival when they got into an altercation with four men.
The men allegedly assaulted her boyfriend, and when she stepped in to help, was punched in the throat crushing her trachea.