Cal. Prob. Code § 6606

(a) A petition may be filed under this chapter by any of the following:
1. (1) The person named in the will of the decedent as executor.
2. (2) The surviving spouse of the decedent.
3. (3) The guardian of a minor child of the decedent.
4. (4) A child of the decedent who was a minor at the time the decedent died.
5. (5) The personal representative if a personal representative has been appointed for the decedent’s estate.
(b) The guardian of a minor child of the decedent may file the petition without authorization or approval of the court in which the guardianship proceeding is pending.