All graduate students are considered independent for the purposes of the FAFSA. Your age, marital status, and whether or not you have been claimed as a dependent on your parent's federal income tax returns do not matter at all.Edit: Not having any reportable income, or W2 forms, is not a problem, and is in fact probably a very good thing. Your EFC will almost certainly be 0.
If a school requires parents income information, it is usually just for institutional need-based aid i.e. scholarships or loans. Your actual EFC for FAFSA will only be based on your income.