If the party desiring the writ of partition is of full age and free from disability, he may make the application either in person or by his agent or attorney in fact or at law. An application may be made for the benefit of a minor, a mentally ill or retarded person, or the beneficiary of a trust by the guardian of such minor, the guardian of such mentally ill or retarded person, or the trustee of such beneficiary, as the case may be.