The law requires that an attorney be appointed by the court to serve as guardian ad litem for the child. This attorney's job is to investigate and report to the court whether the adoption is in the best interests of the child. This requires the guardain to interview the adoptive parents and the birth parents and to read the Home Study Report.
In most cases, if things are proceeding normally, the guardian ad litem appears on the date of the Consent Hearing and is not involved either before or after that date. Since the adoptive parents have already been approved by the agency that did the Home Study, it is unlikely that the guardian will have any concerns about the adoptive parents. He will want to be assured that the birth mother is making an informed and appropriate decision. If the birth mother is represented by counsel, then the guardian most likely will not feel it necessary to interview her to any great extent.
There are situations where unusual circumstances exist which may lead a guardian ad ltem to paly a much more significant role. Certainly this is true in contested adoptions.