The attack is said to have taken place on May 25 when independent senator Lydia Thorpe attended an Australian rules football match in her hometown of Melbourne.
Ebony Bell, 28, appeared via video link in the Melbourne Magistrates Court. She has been charged with two counts of recklessly causing injury and three counts of unlawfully assaulting a stadium.
A police statement described the 51-year-old senator’s injuries from the alleged attack as “minor”.
But she said in a statement to The Associated Press on Monday that she “suffered serious nerve and spinal injuries in my neck, which required spinal surgery and a plate.”
The assault was reported to the police the following day and Bell was arrested on 25 July.
The women knew each other, but the motive for the alleged assault was not explained in court.
Bell’s lawyer Manny Nicolosi told magistrate Belinda Franich that the prosecution’s case had “real flaws”. He said on Friday prosecutors made an “offer,” apparently a reference to a plea deal.
“I haven’t had enough time to really consider it,” Mr Nicolosi told the court.
Mr Nicolosi explained that his Indigenous client had not appeared in court in person due to “recent threats”. The lawyer did not elaborate on those threats.
Bell remains free on bail pending a court appearance on November 22. The magistrate agreed to allow her to appear again via video.
Thorpe made his first public statement about the alleged assault after hurling abuse at Charles during a reception at the Australian Parliament House in Canberra last week.
“You are not our king. You are not a sovereign,” Mrs. Thorpe shouted at Charles as she was led from reception by security guards.
“You committed genocide against our people. Give us back our land. Give us what you stole from us: our bones, our skulls, our babies, our people,” she added.
The main opposition party called on Ms Thorpe to resign from the Senate over her treatment of Charles, who is Australia’s head of state, and sought legal advice.
Ms Thorpe is known for high-profile protest actions.
When she was confirmed as a senator in 2022, she was not allowed to describe the then monarch as “colonizing Her Majesty Queen Elizabeth II”. She briefly blocked a police contingent at Sydney’s gay and lesbian Mardi Gras last year by lying down in the street in front of it.
Last year she was also banned for life from a Melbourne strip club after a video surfaced of her shouting abuse at male patrons.
She revealed her injuries after The Australian newspaper reported she had missed 16 of the Senate’s 44 meeting days this year.
“I have been advised not to travel by my doctor and have been unable to attend Parliament after sustaining the injury and while recovering from surgery. My doctor told me to take time off from work,” she said in a statement.
“I would prefer to keep this matter private and will not comment further at this stage,” she added.