A family affair?
So I'm in good company: who counts and who is decorative is clear as water. (I confess I do not know the specific gravity of blood vs. water, but evidently blood doesn't count for much in the photo op category.) Family there was defined as the relatives who will be in the Christmas (yes, Christmas) photo sent annually by my aunt and uncle (the bat mitzvah girl's maternal grandparents.) Genetic links were strictly by request, and I didn't fall into the pool.
Might I suggest that your granddaughter's bat mitzvah may not be the most "appropriate" location for a secular Christmas photo? That it may be an insult to the child who has worked long and hard to learn Hebrew, study Jewish history, chant a Torah portion, and understand the cultural traditions in which her immediate family is raising her?
What the photo op suggests about my cousin, age 52, and her husband is that they don't think they can afford to decline participation in a photograph manufactured to celebrate a holiday antithetical to their own religious practices. Or, they fear being cut out of the will.
Whatever other motivating factors exist in my family, generally money talks. It speaks volumes. In this case, apparently the photo op is part of the price of having one's parents pay for one's children's private-school education.
Perhaps not coincidentally, the one cousin I love and his family have never taken a dime from his parents. They are the family with whom I celebrate Christmas. It's a holiday I was raised with, and, no, Jesus has nothing to do with it.
We are long-time assimilated German Jews. That's my heritage, Christmas tree and gifts included. Hanukkah presents are sold to a completely separate audience, although my mother and I have been known to light the occasional candle.
My cousin's wife is Protestant, and while it has been hard for her to grow accustomed to Christmas as a secular occasion, she is more than happy to welcome me for their festivities.
I wished her children a very happy Halloween. The little one is going as an angel.