Cal. Education Code § 25915

(a) “Dependent child” or “dependent children” means a member’s unmarried offspring or stepchild who is not older than 22 years of age and who is financially dependent upon the member on the date the member becomes eligible for benefits pursuant to this part. (b) “Offspring” shall include the member’s child who is born within the 10-month period commencing on the date the member becomes eligible for benefits pursuant to this part. (c) “Offspring” shall include a child adopted by the member. (d) “Dependent child” shall not include the member’s offspring or stepchild who is adopted by a person other than the member’s spouse. (e) “Financially dependent,” for purposes of this section, means that at least one-half of the child’s support was being provided by the member on the date the member became eligible for benefits pursuant to this part. The system may require that income tax records or other data be submitted to substantiate the child’s financial dependence. In the absence of substantiating documentation, the system may determine that the child was not dependent on the date the member became eligible for benefits pursuant to this part.