Thank you everyone for your wise replies.  She didn't show up and no one even mentioned it.  My son's girlfriend posted a picture on Facebook of him hugging two little girls belonging to a friend that they had dinner with.  The picture was posted with the caption "family."  I wrote back and said that he has family:  parents, siblings and his own child with a grand child on the way, unles he had disowned us all.  This started a barrage of cursing and name calling from the girl's mother (the friend) and from his girlfriend who originally posted the pictures.  I just responded today and said that I had invited them to dinner, having not spent a single holiday with them for over 10 years.  They never responded to the invite.  The didn't call to say Happy Thanksgiving nor did they respond when I sent a message wishing them a happy holiday and wishing they were here.  So, when I saw this post, I was really hurt.  I told this to my son.  Ten to one, he won't even respond to this either because he learned from me as a child that you don't talk about problems.  It's hard when you see your adult kids acting out the dysfunction your taught them when they were little.  (Always a good possibility that he is agnry about something, probably justified, but not dealing with it.)  Not much I can do about it, but it's sad to have this much distance and noncommunication.  Just not a healthy or happy way to live.  Anyway hope people had a reasonably happy Thanksgiving, and again, thanks for giving to me!!