Whenever a minor or an incapacitated or partially incapacitated person has a guardian of his estate residing in this state, personal service upon the guardian of any process, notice, or order of the court concerning the estate of the deceased person, in which the ward is interested, is equivalent to service upon the ward. It is the duty of the guardian to attend to the interests of the ward in the matter. Such guardian may also appear for his ward, and waive any process, notice, or order to show cause which an adult or a person of sound mind might do.
Okla. Stat. tit. 30, § 4-704