The only person responsible to pay your husbands child support is your husband so no, she cannot attatch any property or banking accounts in your name only - this is why it is wise not to jointly own anything with someone who owes debts such as child support.
If he owes the back support now would be a good time for the two of you to be figuring out how he will pay it -- you may end up carrying a large portion of your family's financial burden until he has paid the debt (while they can't touch your property or finances they will take it out of his income and that will leave many bills his pay would normally cover as unpaid and it would then fall on the two of you to figure out how to pay them.) The sooner he is able to pay the debt the better so I hope you will be able to come up with a plan to allow the both of you to be out of the shadow of the debt ASAP....not to mention it is in the child's best interest to have the support paid so that they can be properly provided for.
Good luck and God Bless
