Ex Spouse filed bankruptcy

Someone please help! I have been divorced for 8 years, in my divorce papers it says my ex wife is solely responsible for any unpaid medical bills for our two minor children. For seven years she has only listed my insurance which is secondary and my insurance would not cover the medical bills because she did not run the bills through her insurance first. i hired an attorney to take her to court for contempt and as soon as i did she filed bankruptcy on all the medical bills. Now they are coming after me to pay these bills most of which are 3 years or older. My insurance won't pay old bills and she won't give me her insurance information and now my attorney says due to the bankruptcy I can't touch her and I have to pay all these bills out of pocket. On top of that she raised my support again. I do not want to file bankruptcy but I can't pay them. There is approx. $5000.00 worth of unpaid medical bills. Can you file bankruptcy on your kids medical bills? I know you can't on back child support. Someone please help me. Also my ex remarried and recently started using my last name again. Is this legal. She has since divorced her second husband.I live in Ohio. Thanks for any help or advice. Also my son obtained a credit card and he is only 17, he lied about his age on the application can they hold me responsible for this card. I do not know what company it is through so i cannot contact them to cancel it. Good Luck to everyone, Crazy Ex.