THANK YOU for all of your replies. I'm so glad I have this place for a sounding board! Hugs all around! I've been reading your replies over the past couple of days and you have helped me in determining how I'm going to handle this. (AHorseSoul -- regardless of what I do, I'm BUYING that book for my own kids for starters - then maybe we'll put it out on loan to these other kids!! That's GREAT!)
I think what I am going to do is gift them an overall present for the family -- likely food/treats. This may be the last year but it will make ME feel better at the holiday knowing I took the high road. I've already had this discussion with my kids and they agree. Keep it simple, gift them "something" - but no individual gifts this year.
This thread has given me yet another direction to ponder though. What if I gave them an experience? One they could ONLY redeem if they came with US. Hmm... Forced time together -- possibly time to repair the relationship between the kids. Time to talk and clear the air. It couldn't be a movie. That's too material and no time to talk. (Maybe a nice visit to volunteer time at the homeless shelter?!)
I do want to believe the nice kids are still there, deep inside. Maybe if we could get them separated from Mean Girl.... but that could just be me in denial. My kids have moved on, do I really want to drag them back there and risk them being hurt again once the holidays have passed? Not really.