"Chabert smokes the most but doesn't look IRL at all. Miner has one inhale/exhale each on a joint and cigarette and looks like she could be IRL. Holly has one drag and exhale on a cigar"
"Given that Lacey Chabert is probably not IRL, she gives a pretty good performance. There are several nice closeups of her dangling a cork-tip and at least pretending to inhale. There is also a sequence in which she is in closeup but out of focus: she lights up and has a few brief exhales, including one nice nose exhale. She also has a couple of decent exhales, in closeup, from a 'joint.'"
Other references to this movie:
Lacey Chabert - Info - video, Fatwa (2005), youtube, c. '05
, Allposters.com