I understand this can be difficult especially at this time of the year. My advice would be to not react to the ex-wife emotionally. I would limit my communication with her as little as possible. Don't give her any fuel to throw on the fire. Allow your attorney to handle this through the courts. That's the only way you're going to win this. Be patient, your daughter probably understands exactly what's going on.
There is no other valid advice than this. ^^^