You cannot sign over your parental rights unless there is a stepmother and she is willing to adopt. Being the NCP does not let you offf the hook legally.
If this girl is in some trouble, then perhaps you should be talking to DSS or see an attorney to see about getting the child in counselling.
If you think she might be better off with you, then file for custody.
Attempting to sign over your rights is a terrible thing to do at this age, she would be a legal stranger to you and it is pretty likely the courts will not allow it at this late in her life.
You cannot sign over rights just to let you off the hook BUT if Dad is the CP he does have most of the responsibilty here, but does not let you off the hook completely.