WR, I would just ignore the behavior and let it go. They are just trying to get under your skin and get you to react. You handled the comment quite well. She certainly can't say that you came back to her in a negative way. Just be yourself and let them stew in their own juices. I have nice huge black cauldron that would do well for them all to have a stew. LOL!
Consider the sources and realize that they don't have anything else better to do but follow you. Obviously you are and have been the topic of conversation this holiday season and what better way to see what you are up to but on FB. Again, you are taking up a lot of room in their heads free of charge. LOL! Whatever you do, don't let them see you sweat. They want to rattle your cage and get you to argue w/them...don't do it. You are far better than that. If they knew that they had rattled you a bit, they would have a good laugh and continue to do so...kind of reminds me of bullies just a bit.
I do hope that once the holidays are over, they'll settle down and get back into their routines and leave you alone. Try not to think about it and consider the sources and go on w/your holiday festivities. They aren't happy people if they have to aggravate others.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.