Can a NJ public school, refuse enrollment to a child in fist grade, when enrolled by her grandparent who does not have legal custody?

This child is my grandaughter, she is almost six, attempting to enroll in first grade. I do not have legal custody of her yet. Her parents are not in the picture. NJ Statues support my status and the childs. The school, refused (the principal, then the loacal BOE) to look at the law, instead said go get legal custody when the statue specifically spells out what needs to occur. The policy indicates that this child - is or will become an affadavit student. The Superintendent, nor the school offered no remedies. They were content with allowing her not to be enrolled, even though - I founf out later - they should have offered the form, enrolled and asked questions later. They violated this childs right to a education, and state law that supported my right to enroll my grandchild who I am the primary caregiver for. They asked questions, prohibited by law. Refused to enroll her. Told me to get legal guardianship, all when the state says they should not.