Police said they found methamphetamine at a house in Orange County where Nadia Lockyer, 41, was staying with her 9-year-old son.
A district attorney spokeswoman said police in Orange received a tip last week leading them to the house. Lockyer wasn't home, but police said they found methamphetamine and smoking paraphernalia.
Lockyer resigned from her Alameda County supervisor seat in April following a string of bizarre public incidents that she blamed on chemical dependency. Bill Lockyer, 71, has filed for divorce and is seeking joint custody of their son.
Nadia Lockyer pleaded not guilty Aug. 30 to a felony count of drug possession, two misdemeanor drug charges and one misdemeanor count of child abuse, because she is alleged to have kept the drugs in the home with her son.
She was released on her own recognizance to a drug rehab center and is due back in court Monday.
The Associated Press contributed to this report.