Unsolved adoption

I think you need to take a step back on this case. I believe the woman you spoke to is not the biological mother. One connection that a brother was adopted from the same home - predictably several years apart - is actually no coincidence. It would be more likely that the Grandmother of the original case may have information - as they were the ones involved with that adoption facility. Do you know if there were other adoption agencies closer to the area she is meant to be from? Do you have a rough idea of the bio father’s age at the time of the birth - the mother may not even be a local if he was as prolific a guy as others claim. There’s bound to have been local events that would bring people further away from the town to visit it. Your choice to “give up and hope for a DNA test” is not about serving your client. You just feel frustrated and haven’t found a way through. That’s not fair on the client.