Sources close to Lindsay tell TMZ .... she's "passionate" about mentoring some of the troubled girls she's met in rehab. Lindsay has taken a genuine liking to the girls -- writing them inspirational notes and giving them advice. Ironic, we know.
As for life in rehab, one source close to Lindsay describes it as "full-on 'Girl, Interrupted'." We're told Lindsay gets no special treatment -- if anything, nurses are harder on her to show they're not playing favorites.
LiLo doesn't have a window in her room and she can't change the channels on her TV because it's behind glass.
A room at the Chateau, it ain't.