Thank goodness they didn’t see Avatar!
Maybe I’m just a wuss but I have a hard time chugging vodka. Am I the only one here with that problem?
Nevertheless, "half-a-bottle" depends on what kind of bottle. She had it in her purse. Assuming it wasn't one of these monstrosities that doubles as a shopping bag, it was probably a pint bottle (8oz), meaning half of it was 4 ounces. Over the course of a 2-hour period (movie plus-or-minus shorts and ads), she was consuming the equivalant of two "doubles" in two hours.
That's a lot, granted, and it explains her BAC.
But let's not get TOO carried away with the hyperbole. It's not like she was sitting around the theatre with a fifth and knocking it back.
I think.... :)