Marionettes are shown being served beer (which obviously isn't real as it's a puppet show).
The Baroness smokes cigarettes in a couple scenes. Then again, America rated this G back in 1970.
There is a formal party where the guests are drinking champagne and other alcoholic beverages.
During a song, the oldest daughter (16) asks the Captain if she can taste champagne. He refuses.
It's insinuated that some pink lemonade the adults are drinking has alcohol in it, commenting "...its not too sweet . It's not too sour. It's just too pink"