Close the credit card in her name and close the home equity line of credit. This is your problem if your name is on it. She has run thru the money and you are funding it, stop kidding yourself. You do have power, you have the money stop giving it to her. Start protecting yourself and your kids from a financial mess. I would recommend going to see a attorney before she comes back to see you. I bet she is bringing the MIL for more than her fear of flying.
M22,H45,W45 S21/18D12 Retain faith that you will prevail in the end, regardless of the difficulties and at the same time confront the most brutal facts of your current reality, whatever they might be.