If her bankruptcy was filed more than a couple of months ago, all you can do is file a claim, assuming that the bankruptcy trustee found any assets to distribute to creditors. Experience is an expensive form of education, but at least you didn't marry her! Hope this perspective helps!
File a claim in bankruptcy court if the bankruptcy has not been filed very long. Also, if she made representations to her friends and others that she never intended to pay and had intent to defraud you or the credit card companies you may have a claim to have these debts set aside in her bankruptcy and the court can hold her liable. You should consult with bankruptcy counsel soon to help you through this process.
You don't want to spend more money pursuing this. I can imagine a scenario where you chase the case down in hopes of having the debt be deemed non-dischargeable based on bad faith or fraud etc.
I don't see that as something that will ultimately lead to you being more happy. Basically, the best case scenario is you make your lawyer's wallet fatter, you make your ex pay some more money.
Do you really want to spend money just to have your ex spend money? Be happy that she is out of your life. How much is that worth? Priceless I'd say!
The above is general legal and business analysis. It is not "legal advise" but analysis, and different lawyers may analyse this matter differently, especially if there are additional facts not reflected in the question. I am not your attorney until retained by a written retainer agreement signed by both of us. I am only licensed in California. See also avvo.com terms and conditions item 9, incorporated as if it was reprinted here. Please visit my web site: www.avanesianlaw.com for more information about my services.