My mom relinquished her rights to me 12 years ago and gave my dad sole custody.

Is this something that is kept on record?
Is it public?
if no one goes looking for the documents, will I be treated as her offspring in case of her needing a power of attorney or guardian fo rher minor child (my sister)?
they went through purchase drugs online an attorney. she gave up her rights in exchange for not having to pay child support.