If you're looking for ideas for what to write in a family Christmas card, here are a few suggestions:
Merry Christmas to our amazing family. We are so thankful to have you in our lives and are looking forward to spending the holiday season together.
Love, The [Your Last Name] Family
It's that time of year again! We are so grateful for the love and support you have shown us throughout the year. We wish you all a Merry Christmas and a Happy New Year.