I think I would overlook it and let her pay as she offered to do. Have a pleasant Christmas without resentment on either side. BUT...I would definitely have that talk with her after the holidays. Maybe you could appeal to her "loving" side and not make it like a "duty"?
I don't know your daughter but when I read your post I did find it rather unbelievable.
I guess I'm one of the lucky ones, my daughter and sons bend over backwards for us....if ever my daughter pulled something like this I would be terribly hurt and would let her know how it affected me.
Maybe it was a spur of the moment reaction on her part, kids can say or do thiongs without thinking sometimes.