California Code, Penal Code - PEN § 3416

(a) If any woman received by or committed to the Department of Corrections has a child under six years of age, or gives birth to a child while an inmate under the jurisdiction of the Department of Corrections, the child and his or her mother shall, upon her request, be admitted to and retained in a community treatment program established by the Department of Corrections, subject to the provisions of this chapter.

(b) Women transferred to community treatment programs remain under the legal custody of the department and shall be subject at any time, pursuant to the rules and regulations of the Director of Corrections, to be detained in the county jail upon the exercise of a state parole or correctional officer's peace officer powers as specified in Section 830.5, with the consent of the sheriff or corresponding official having jurisdiction over the facility.