(a) 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) an agent having authority to act with respect to the particular question or dispute may represent and bind the principal;
(3) a trustee may represent and bind the beneficiaries of the trust;
(4) a personal representative of a decedent's estate may represent and bind persons interested in the estate; and
(5) a parent may represent and bind the parent's minor or unborn child if a conservator for the child has not been appointed.
(b) If a disagreement arises between parents seeking to represent the same minor child:
(1) the parent who is a beneficiary of the trust that is the subject of the representation is entitled to represent the minor child;
(2) if both parents are beneficiaries of the trust that is the subject of the representation, the parent who is a lineal descendent of the settlor is entitled to represent the minor child;
(3) if neither parent is a beneficiary of the trust that is the subject of the representation, the parent who is a lineal descendent of the settlor is entitled to represent the minor child; or
(4) if neither parent is a beneficiary or a lineal descendent of the settlor of the trust that is the subject of the representation, a guardian ad litem must be appointed to represent the minor child.