If she declares bankruptcy, she may still be required to pay for a percentage of the debt, based on her income and any assets she has.
If this were me, I would say that she needs to show you documentation of the terms of bankruptcy so that you can see what percentage of the debt still exists. Then you can pay her half of that percentage.
At a personal level, I would be thinking that she had the option of declaring bankruptcy all along, and the payments made so far have just been going down the toilet. Resenting something isn't always the best way to make a decision, but I would use that to feel firm that she needs to give me full disclosure and I need to see exactly how much I owe toward outstanding debt.