If you boil Chicken stock that has been in the refrigerator for 12 days will it be OK?

No, it is not safe to boil and consume chicken stock that has been stored in the refrigerator for 12 days. There is an increased risk of food poisoning due to bacterial growth over such a long period of time. It is generally recommended to use any cooked or refrigerated broth or stock within 3-4 days for optimal quality and safety.