No not under family law.
One you knew that the market conditioins would greatly reduce the realized value of your home, and thus make the settlement terms inequitable, a petition should have been filed at that time for a modification of the terms. Since the stated value in the agreement was not going to be reached, what was the compelling reason to complete the sale?
You need to determine the basis of the court decision to justify termination of parental rights. Your facts do not indicate that abandonment, neglect, non-support, or abuse was involved in the case so it is hard to justify termination of parental rights. What was in the pleadings received in your summons"? There has to be something in the record that you are not aware of and I would check on that. Additionally, there has to be proof that you have been served and had full knowledge of the...