Legal Question in Real Estate Law in Maryland

Unfortunately because the agreement you made does not entitle you to recoup your investment until your former inlaws die and the property is sold, you will have to wait for that event and then file a claim against the estate of the last to die. Even though the building was destroyed, they still own the land and could rebuild. Of course, there is always the possibility that they will try to deed the property over to your ex, someone else, or just sell it to avoid your claim. To protect yourself, you will have to monitor that situation, which will be hard to do unless it's being publicly marketed. If at the time of the initial investment you had been given a deed of trust to record against the property to protect your interest, you would be protected against this now. As part of the divorce case, it would have been wise to try and resolve that issue with your now-ex by trying to get her to buy out your interest in this investment, or if unable to agree, to ask the court to consider it as part of the property distribution aspect of the case. That explains why she's unwilling to negotiate with you now, as there is no pressure on her to do so.