Ooooh, oooh, oooh.
I finally found two movies I can recommend.

My Life So Far
Upper Class Scotland in 1920, but saying upper class Scotland is sort of like saying ...
Intellectual Boz
It's all relative, isn't it, cute movie, hot chicks with crooked teeth, and just the right amount of angst.

Lost and Delirious
Lesbianism run rampant in an exclusive girls boarding school in Canada.
Actually, I've only watched the first ten minutes of it. I had to stop because the basketball game was about to start.
Teenage girls, in knee socks and school uniforms, they smoke, they swear, they drink, they party, and did I mention lesbian sex.