Lindsay Lohan is said to be "extremely focused" on her court-ordered therapy sessions.

The controversial actress is set to go before Los Angeles Judge Stephanie Sautner at court on Wednesday (19.10.11) where she faces up to 18 months in prison after allegedly skipping some of her probation requirements, which were issued as part of her sentence for stealing a $2,500 necklace in January.

The 25-year-old star - who previously served 35 days under house arrest for the offence - was forced to change her community service schedule last week after reportedly failing to turn up for community service at Downtown Women's Center on a number of occasions, which led to her being reassigned to the Red Cross.

Lindsay's representative Steve Honig told RadarOnline: "Lindsay performed community service every single day this past week at the Red Cross, and has been spending the bulk of the weekend fulfilling her therapy and shoplifters course requirements. She is extremely focused on her court-ordered obligations."

An insider added: "Lindsay is really starting to rack up The Hours now and is extremely serious about getting this done."

But Lindsay - who recently spent time working in France and Italy - denies skipping her weekly therapy sessions, claiming she carried them out over the phone.

A source close to the actress explained: "Lindsay was ordered to undergo weekly therapy sessions by Judge Sautner. Technically, Lindsay isn't in violation of that order, because Judge Sautner didn't specify that these appointments be done in person.

"It's assumed that Lindsay would go see her therapist every week, but there isn't a specific order stating how that session is to be conducted. Lindsay always pushes the envelope, No Doubt. Judge Sautner will most certainly modify terms of her probation at her progress report hearing.

"Even if Judge Sautner revokes Lindsay's probation on Wednesday, and remands her into custody, she will post bail immediately. Lindsay must be given bail because it's a misdemeanor, and there would be a probation violation hearing, and that is when it would be determined by the judge if she should go to jail. Again, this is only if Sautner determines there appears to be a probation violation."