In Massachusetts children are considered to be incompetent legally, meaning making a decision such as whether or not to waive their Therapist Patient Privilege.  A GAL would be appointed to not just ask the child what his/her position is, but to substitute their judgment for the child to determine whether or not it would be more beneficial for the Therapist Patient Privilege to be waived or not.  The GAL usually talks to the therapist, the child, the parents and some other collaterals and then make a written report with a recommendation whether to substitute the judgment to waive that Therapist Patient  Privilege or to determine that the confidential information and therapeutic benefits of keeping it confidential outweigh the propriate value for the court and finding out what is going on during those therapy sessions.