Survivors and College Question?

My father died when we was younger and he owned a construction company. My little sister is 16 years old and is graduating high school next year in June 24th, by then she will be 17 since her birthday is on January 27th. But anyways she is thinking about taking a year off and enrolling when she is 18 years old. But she is afraid she won't be able to get survivors from social security! Will she? Should she take a year off?