Photographers caught the troubled star, who is due to appear in court on Wednesday on felony theft charges, coming out of a Los Angeles hotspot.
Lohan, 24, said she had just gone to see a friend, Jordanian-American singer Ferras Alqaisi.
'Went to see my friend @ohferras perform and was talking to a future co-star - just to be bombarded by paparazzi - so much for being normal,' she wrote on the microblogging website afterwards.
The actress could be jailed for three years if she is convicted of stealing a $2,500 USD necklace.
It follows reports she is set to sign up for her first post-rehab acting role - in a movie about celebs who can't handle fame.
Director Nathan Folks told gossip website RadarOnline that he has cast the star in Escaping The Game.
She will play an investigator probing suspicious celebrity deaths and disappearances.
'She wants to do it,' he said. But she will have to get her own minder for the shoot.
Folks added: 'We can get her insured if she is with someone who is keeping an eye on her 24/7.
'Lindsay and I've discussed it and she's already agreed to the condition.'