When Caroline is telling Max that the asking price for a cupcake is 7$ in Manhattan and they should sell it for 7$ instead of 5 and pocket the difference, when the camera is turned to Max you can see the price on the tray at the diner to be 1.50$ for cupcakes.
Caroline mentioned that she borrowed shoes from Sophie. Sophie hadn't moved in yet.
After Caroline's kitchen encounter with Max's slutty boyfriend, she reaches around him and removes her uniform from the sink. As she stops to tell him 'she's seen better', she holds her uniform out, and while it is covered with suds, there is no water dripping from it.
Caroline claims to have scored 2300 on her SAT. The max possible is 1600. Its not clear if she was lying, exaggerating, or the writers made an error.