I have a new grandchild with my sons girlfriend. They live together and I have always treated her like a part of our family.
She ignors me, and does not care if we see the child or not.
She has made the decision to not participate in our christmas traditions this year.
How do I deal with an absent grandchild, or more importantly how do I communicate with a daughter in law that does not care about our families traditons?

Why not try communicating with your son?

But in the end, she has her own family as well.

Yes it is sad.

So talk with your son.

Perhaps next Christmas it can be spent with you.