You did a very good job of holding it together. I know it had to be tough discussing the decree on Christmas day and what needs to be addressed as to custody, etc. I am very proud of you!
Now, it's on to getting your stuff out of her brother's house and into your apartment...at least your stuff won't be held hostage again if she throws another ranting fit.
Try to enjoy the rest of the holidays. You and your family deserve a little be of peace.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.