Christmas is a good day to take a break from your research and focus on the living relatives. It also brings to mind another tip.
Take a break from that family or problem that really has you stonewalled. Work on another family for a while, putting the brick wall group aside for a week or a month. It may be that when you come back to your problem, you notice something you did not notice before. Perhaps when working on another problem, something will dawn on you regarding the original problem.
In the back of your mind the original problem is there and something totally unrelated to your research problem may cause you to have the breakthrough idea you need. Sometimes what we need most is a little "away time."