Lohan, 24, strolled into a local Palm Desert, Calif., mall on Wednesday with an unidentifiable female. She headed into Forever 21 and bought about $250 worth of loungewear, a source tells PEOPLE.
"She picked out everything on her own," the source says. "She seemed happy and was courteous. She was dressed casual and looked fine."
The troubled actress is ordered to stay at Betty Ford until at least Jan. 3.
Her shopping trip was first reported by RadarOnline.