If they are still married, and she did, in fact, file for 2019, then she would have received the stimulus payments into the same joint account that they've had. Unfortunately, at this point, there isn't much you can do aside from hiring an attorney. I am so sorry that you and your father are dealing with this. You are a very good person for helping out! Definitely file for him! Get him into the system - this way you can find out (without the use and cost of an atty) if she has been filing joint to receive the benefits. There will be a return already on file for him if she has filed and claimed him on her return - or even just simply did MFJ.
