Her estate would be liable for the debts. The creditors would get money before her heirs would receive anything. If her estate has no assets, no one would be liable.
If the dates are post-separation, they are her separate debts, not community property debts. Date of separation would probably be determined by the court's finding in the divorce judgment.
Make sure that your name is off any credit card account that you had jointly with her.
If there is life insurance, that money would go to the named beneficiary, not to creditors. If she was ordered to buy life insurance for your benefit as a part of the divorce, you should consult the attorney who represented you in your divorce case, or any other family law lawyer, as you might need to take legal action to enforce that provision.