My Husband stole his grandfathers ID and opened credit cards threatening wife also with charges

If you did not spend the money, benefit from the spending of the money, or otherwise participate in obtaining or using the money or the credit cards, and you did not cover for your husband, then you are not criminally liable. What that means is that you cannot be placed in jail. Since your husband is in jail already for the activity, it appears that the law enforcement community believes that only your husband is criminally responsible. The decision on whether someone is charged is not up to the grandparents but is up to law enforcement.

Whether you may owe money is a different question. In Texas, married couples owe jointly and separately, meaning that any debts owed by one are owed by both thus in your situation, someone could seek to obtain money from you.

I question why the grandparents are out the money, though. The credit cards were fraudulently obtained without their knowledge so I would not think that they are responsible for the bills.

I would consult with a family lawyer who will know whether your State is a joint property state (and I would also seek a divorce to stop any further problems this person may cause in the future for you and your children.)

If the grandparents harass you (repeatedly call you, come to your home, or act in a threatening manner, I would report the behavior to the police.)