A challenge to a court ruling that puts Britney Spears' father in control of her assets until July has been dismissed by a US appeal court.
Lawyer John Eardley, who claims to represent the singer, argued she had not been given sufficient notice when the order was granted in February.
A judge in California said it was not within his powers to grant an appeal.
Meanwhile, the singer's guest appearance on TV comedy How I Met Your Mother was screened on Monday night.
In the programme, shown on the CBS network, the 26-year-old played the character of Abby, a doctor's receptionist with a crush on main character, Ted.
The singer's father James Spears was originally granted temporary conservatorship over his daughter in February after she was admitted to a psychiatric ward.
A US court creates a conservatorship when a person is unable to care for themselves.
The order, which puts Mr Spears in charge of his daughter's assets and estate - thought to be worth $100m (£50.8m) - has since been extended to 31 July.
In his challenge, Mr Eardley said a "five-day notice requirement" had been dispensed without "legitimate grounds".
Mr Eardley has claimed Ms Spears employed him during a telephone conversation in February.
But under the conservatorship order, she is not allowed to hire a lawyer.