Factual error: As a college student this has always bothered me. It is impossible for a first year student to apply to a school as prestigious as Columbia University in the MIDDLE of the summer and not only receive admission, but a FULL-RIDE scholarship. A quick check on Columbia's website revealed that the deadline for ALL students was May 15 and most of the scholarships given out come from outside agencies, not the school itself. Even though Ana's teacher said he has a friend up there, there is still no way such strings can be pulled in that short amount of time.
Continuity mistake: The scene where Ana goes to her father to ask for a loan for Estela's factory, each time the camera comes back to Ana, the shadows in the background change.