What should I do about my wife's insistence on celebrating her birthday and our son's, and her demand for congratulations and gifts, despite her knowledge of the ruling on celebrating, and the problems that have resulted from this?

Celebrating Christmas and congratulating relatives on it is forbidden in Islamic law. A Muslim must not congratulate his sister or wife on it if he believes it is forbidden. Rather, he should explain to them the error of this celebration and its contravention of Islamic law. If the wife gets angry because she was not congratulated, she is mistaken, and she should be advised gently and kindly that true love is conformity with Islamic law. "Whoever pleases Allah at the expense of displeasing people, Allah will be pleased with him and will make people pleased with him." There is no obedience to a creature in disobedience to the Creator.