R.I. Gen. Laws § 33-3-9: Representation of infants and persons non compos mentis.

In case any infant or person non compos mentis shall be interested in the partition of any estate as provided in § 33-3-3, the application for the same shall be made and signed by his or her guardian, if he or she has one, otherwise by his or her guardian ad litem appointed by the court, whose acts in the premises shall be conclusive on such infant or person non compos mentis.