I was on as a secondary owner of a bank account opened by my ex. She closed it but had some unpaid fees. As a result of my name being on the account, my credit which is overall very good had been badly dinged by the unpaid fees. Now I have to go prove we paid this fees and go through the entire painful process to fix my credit.
I could not tell if your husband did put his name on her bank account. And it doesn't matter what type of account it is. All can affect Chipmunk's credit which will affect Airyn's credit which will affect your credit since you two are married.
If she has any credit problems now or in the future it will hurt your credit.