Answer: If the student was never actually in foster care, she won’t qualify as independent for the FAFSA as a former foster youth. However, students who were in legal guardianship qualify as independent. Was the guardianship legal, with a court document to back it up?
If so, she should check yes to the legal guardianship question on the FAFSA. If not, she will have to talk to the financial aid office to request a dependency override. The financial aid administrator will make that decision. You could write a letter in support, describing what you know about the student. But it wouldn’t be a verification letter like you write for unaccompanied homeless youth. Given this situation, the financial aid office should grant the dependency override.