Cal. PROB § 3112

(a) If a petitioning spouse is one whose legal capacity for the proposed transaction is to be determined in the proceeding, the court may do any of the following: (1) Permit the spouse to appear without a representative. (2) Appoint a guardian ad litem for the spouse. (3) Take such other action as the circumstances warrant. (b) If a petitioning spouse lacks legal capacity for the proposed transaction, the court may do either of the following: (1) Require the spouse to be represented by the conservator of the spouse. (2) Appoint a guardian ad litem for the spouse.