Just a note that the courts can force you to comply with the existing agreement...especially if you have a 401k or any other assets that they can force you to liquidate to make her whole. Thus,if your ex is not receptive (and BTW - you're divorced. She can choose to not be reasonable if she so desires) I would strongly recommend that you get to the courthouse and file a motion. Then you can lay out the options provided as an alternative to the existing requirement. The judge may perceive that you are reasonable and attempting to do the right thing and grant it. Then again, they may force you to liquidate. I would recommend that if the ex received any consideration related to pension, alimony, etc. as a result of the debt being assigned to you (I'm assuming here that you assumed the debt) that you mention this in your motion as well.
As to whether you would be required to pay for your ex's attorney - anything is possible. However, if you're in fairly similar circumstances it's entirely possible that you would both be responsible for your own fees. A local attorney can provide you with more guidance on that topic.