To the extent there is no conflict of interest between the representative and the person represented or among those being represented with respect to a particular question or dispute:
(1) a conservator may represent and bind the estate that the conservator controls;
(2) a guardian may represent and bind the ward if a conservator of the ward's estate has not been appointed;
(3) an agent having authority to act with respect to the particular question or dispute may represent and bind the principal;
(4) a trustee may represent and bind the beneficiaries of the trust;
(5) a personal representative of a decedent's estate may represent and bind persons interested in the estate; and
(6) a parent may represent and bind the parent's minor or unborn child if a conservator or guardian for the child has not been appointed. The parent entitled to represent and bind the child is determined in the following order of priority:
(a) the parent who is a lineal descendant of a settlor;
(b) the parent who is a beneficiary of the trust that is the subject of the representation;
(c) the parent with legal custody of the child; and
(d) if one parent cannot be determined pursuant to the preceding criteria and if a disagreement arises between the parents seeking to represent the same child, a guardian ad litem must be appointed to represent the minor child.