For a full time college student, the students income is irrelevant. They could earn a million dollars and still qualify as your dependent. It sounds to me like your issue is that you indicated the dependent college student lived with you for LESS than the whole year. Work back through that dependent's information again under the Personal info tab. Then on the screen that asks how long they lived with you, read the small print on that screen so that you will understand why you are changing your selection on that screen to "The Whole Year". Then make the change and continue working through the dependent's information until you get to a screen with a DONE button on it. Then click that DONE button. Your change does not stick until you reach a screen with a DONE button on it, and actually click that DONE button.
