My niece is being harassed the her class, by teacher as well as Other students the principal and administration are not willing to handle the situation
Probably no legal action right now. "Harassment" does not really mean anything and is a term used very broadly and widely defined like "bullying." What is the specific conduct that your niece is being affected by? Insults? What is the nature of the insults? Is she being physically touched? The inappropriate conduct needs to be specific and defined as it will affect what possible legal rights and remedies can be considered (ex: if the insults relate to unlawful discrimination based on race or sex, that indicates civil rights protections; if the conduct involves unwanted physical contact that causes physical injury, it may indicate personal injury state remedies as well as possible requests for police intervention; etc.)
And the school must be on notice of the inappropriate conduct, and you will need evidence that the school is on sufficient notice. The best way to do that is sending written letters describing the conduct, and having proof that the letter was received by the superintendent, the principal, and any other school staff with knowledge or regular interaction with your niece. Make sure to send the letters by certified mail/return receipt requested so you have proof the mail was received.
Without anymore information, it would be difficult to advise what a good next step would be, and what legal resources to consider other than consulting with a local education attorney.
This answer provides general advice and should not be understood as to create an attorney-client relationship between the questioner and the responding attorney.
Years licensed, work experience, educationLegal community recognition
Peer endorsements, associations, awardsLegal thought leadership
Publications, speaking engagementsDiscipline