Speculation is rife as to just how much of Lindsay Lohan's 90-day prison sentence the actress will actually serve.

The 24-year-old was taken to Lynwood prison in California on July 20 for violating probation after two drink-driving offences.

However it is thought Lindsay may only serve about two weeks due to prison over-crowding and good behaviour.

Lindsay's mum Dina Lohan and sister Ali have visited the prison however it is not known whether they were actually allowed to see Linsday.

According to reports, the Hollywood star has slept for most of her first two days behind bars.