Change name on all certificates

Sir.. my parents have adopted a child at when she was 6montgs kid and now she is 24years and we did everything even her marriage in a very grand manner.. within one week of marriage she eloped from there and said she is in love and she don't want any relation anymore all are dead for her and she need to lead her life in her style.. now we also left and we are facing all issues outside.. my parents want to remove theri name from all her documents, as on a good faith ground one person have made her birth certificate with my parents name and from there they have used their name in all her documents.. which now they want to change to her original biological parents name itself and remove my parents name from it in a legal way.. can anyone plz help me with this situation to overcome, as we are confused on changing this as she should never come back in our life in future for any reason or what so ever. Also to mention this girl is taken from my mother's sister.. she was divorced and this girl don't had anyone to take care.. so my parents went forward to give her all love and affection and everything from their name till their life.