A "Guardian Ad Litem" (GAL) is any adult over the age of 18 years of age that is appointed by the court to oversee the best interests of a child.  This is usually a parent, or close family member.  

In my San Diego injury law practice, I routinely set up a GAL with the courts whenever there is a minor's settlement for bodily injuries that is in excess of $5,000.00.  The GAL is appointed to open a blocked account for the minor child with any federally insured banking institution or any Triple AAA rated investment vehicle, such as an insurance annuity for the best interests of the child.  If a bank account is used, or investment vehicle, the child has full access to the settlement fund when he or she turns 18 years old (in California).