VIC Urgent Namge Change for 17 year old without full parental consent

Hi, My daughter is 17.5 years old and has been accepted into the Australian Defence Force (Navy). Before she enters, she want to legally change her last name to the name she has used her whole life. But it is not the name on her birth certificate. Surprisingly, even her learners permit has her preferred name. She understands she must have permission from both parents to apply to Births, Deaths & Marriages in Victoria, but this is not possible given her biological father has been missing from her life since she was 3 years. Nobody knows his whereabouts, not even the police. How can she apply directly to the court to obtain permission to change her name from a judge?