My husband co-signed an auto loan for his daughter without my knowledge. She has defaulted and now they have to go to court for payment. j

As a general rule, parents are not responsible for the obligations of their adult children, and spouses are not responsible for the debts of their spouses (except for what are known as "necessaries", for example emergency medical care; this would not fit in that category.)  Thus, assuming your step-daughter is an adult, you would not be responsible for this obligation.