My little sister lives with me . How can I get her registered in HF high school without having to go to court for it ?

What is the situation that she lives with you? In which state do you live? (needed in order to know laws).

Who and where is her guardian? My friend types up an agreement and has it notarized to take his sons to Georgia and enroll them in school there. They have done it for years. And he is not on the birth certificate.

If this is in the US, you would need a birth certificate, vaccination record, and in many states, proof of custody.

Often it will depend on the school, even if rules say other wise, if this is a transfer, where from, did they go to middle school in same school system. If so, they should just e able to go??

Why are they with you? Who has legal custody ? Where are you at ? Where is parent or guardian at ?

Is this within same school system or new system ? Why can parent not come and enroll them ?