" Grandmother was her legal guardian"
And that’s why her EFC was $0. If you are under a legal guardianship after you are age 13, you can qualify to file as an independent student. If you are a ward of the state, it is automatic. If it is not, you have to provide some additional information.
Student who live on their friend’s coach for a year do not get that designation automatically. They’s have to ask for professional judgment. They’d be better off if they did go into foster care.