Mo. Rev. Stat. § 456.3-303: Representation by fiduciaries and parents.

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 conservator ad litem may represent and bind the ward with respect to a particular question or dispute over which a conservator does not have authority;

(3) a guardian may represent and bind the ward with respect to a particular question or dispute if a conservator or conservator ad litem is not authorized to act with respect to that particular question or dispute;

(4) a parent may represent and bind the parent's minor or unborn child if a conservator, conservator ad litem, or guardian for the child has not been appointed;

(5) an agent having authority to act with respect to the particular question or dispute may represent and bind the principal;

(6) a trustee may represent and bind the beneficiaries of the trust; and

(7) a personal representative of a decedent's estate may represent and bind persons interested in the estate.