Regarding the Islamic ruling on attending birthday ceremony or non-Islamic events of non-Muslim family members, Dr. Main K. Al-Qudah said:
If you realize that joining your non-Muslim relatives in their birthday’s parties will bring you closer to their hearts, then you can join them while observing your Islamic personality and not getting melted. However, it is not the case for celebrating Thanksgiving or Christmas, because these two occasions – and some more- are religious ones, while birthdays is a tradition and not a religious event. Obviously, a Muslim does not celebrate any religious holyday except the two Islamic feasts.