Amanda Bynes' parents will ask a court to grant them conservatorship of their daughter tomorrow.
The troubled star's estranged parents Rick and Lynn are increasingly worried about Amanda's erratic behaviour and have arranged a hearing at Ventura County Courthouse in Oxnard, California, in order to secure legal control of her personal and financial affairs until she gets her life back on track.
Amanda, 27, is currently undergoing a psychiatric evaluation after being admitted to hospital on Monday (following her arrest for lighting a small fire outside an elderly woman's home.
A source told RadarOnline.com: "Rick and Lynn will appear before the judge on Friday to ask for a temporary conservatorship of their daughter, Amanda. Her parents will both be petitioning to be the temporary proposed conservators, and want control of her personal and financial affairs."
Amanda's parents are hoping to prove their daughter is a danger to herself and will have to provide evidence of her increasingly bizarre behaviour in recent months, which they believe shows signs of Schizophrenia.
The legal insider added: "The proposed conservator must show that the conservatee is unable to care for themselves, and is a danger to others.
"When Britney's father got conservatorship of her, she was viewed as a danger to herself and this made it much easier for the judge to sign off on it."
The 'Hairspray' actress will not be charged for the fire in Thousand Oaks, California - during which she accidentally soaked her Pomeranian puppy in gasoline - as officers realised she needed professional help rather than a legal punishment and secured a 5150 hold.
Rick and Lynn are said to be "sick with worry" and have been told to act quickly while Amanda is being held in hospital for up to 72 hours.