Your reversion to Islam is encouraging. May Allah Ta’ala accept it and keep you steadfast, Aameen.
According to the Shari’ah (Islamic Law), it is not permissible to celebrate Christmas or any occasion which is a salient feature of the non-Muslims. You know your family well and you should apply your discretion in dealing with them. We suggest you have to practise on Islam and maintain family ties without compromising on your Islamic values. This attitude and conduct should be presented to the family with wisdom as soon possible so that you do not be burdened in future.
and Allah Ta’ala Knows Best
Mufti Ebrahim Desai