I helped my sister open a bank account through my own chase account years ago. It never occurred to me that anything that took place on her account would effect me. She was recently involved in a scam that leaves Chase out of $9000. I was told that my other checking and savings account that has $3900 in it will be closed and I may not get the money back. Is this what typically happens in these situations?
Presumably, what happened is that you and your sister were co-owners of the account. That means you have equal rights to the account, and also equal responsibility, such as liability arising from fraud. For example, if A writes NSF checks for $10,000, both A and B can be held liable for that debt, plus the fees, and it does not matter who actually wrote or passed the check. As a co-owner, you are fully liable for the debts of the account.