While people say it's a wonderful time of the year, it's actually extremely stressful. Try to reach out neutrally, and hopefully she will apologise/realize/take back what she said so it's a nicer week for you two. Some days can be like that, especially if you're both working and just want to relax! We as humans sometimes need something to blame, even though it wasn't the reason. Doesn't excuse the attitude, just saying it does happen.

It's too bad the bars are closed these days. Otherwise, you could have gone to one on Christmas Eve, find a ho, ho, ho and get into her stockings -- if you know what I mean. ;)

How does you dropping your kid off have anything to do with her dropping hers off? Do you do everything on a mine/yours basis? If so, I feel extremely bad for the children.