Well she is not huffing CFCs she was huffing HCFCs R-22 or Chlorodifluoromethane this is what they will do to you
http://www.inchem.org/documents/icsc/icsc/eics0049.htm .
People huff to get a cheap easy high it reduces the oxygen to their brains and makes them feel high.Some people will huff any type of spray can paint or the air cans for cleaning of electronics but they started putting a bittergant in those so people will huff cans of whipped cream.People also huff model glue and white out that was very popular when I was in high school thye would paint lines on a sheet of paper and sniff it I even saw kids huff markers.I think it boils down to parenting my parents would think such things are stupid and foolish and I never wanted to be stupid or foolish. Of course huffing anything means that you run the risk of suffocating yourself this is much more likely with an A/C system do to the amount of refrigerant because of the amount that could leak out (all that is in the system).Now the up side is maybe this girl is really really stupid and thinks that the "good stuff" just comes right out of the vent if you are close enough which it does not.
For this girl it is nothing new at all I would suspect.And there is nothing that you can do about it I have a friend that wanted to report a woman abusing drugs while pregnant to the state they said "nothing we can do about that".So do not worry about is all I can say because there is not a thing that really anyone can do about it and what would they do put the girl in jail unless she is watched 24/7 nothing will stop her anyway.I think if you are a known drug abuser they should sterilize you so that you can not harm people that can not protect themselves surely this would cost governments less money in the long run.
@Gimpy117 every generation has an equal share of turds it just depends on who you are around and if these kids that you know are having kids and not taking life seriously and the grandparents are taking care then I blame the grandparents they failed to instill good values in their children.Just look at the statics the highest rates of teenage pregnancy was in the 1950s which always makes me laugh we people say "this is it not the fifties any more things are different now".