I'm about to be 50 years old, a fact which defies my comprehension... but I tend to think a lot younger in most ways. Body piercings, however, are not among those ways, and excessive tattooing also bewilders me.
Nonetheless... my mom has a favorite restaurant that I take her to all the time, and our favorite waiter there is a delightful 20-year-old boy who is engaged to the delightful 20-year-old hostess. They are two of the nicest people we know, and we've gotten to be friends with these two sweet kids -- despite the glint of gold tongue jewelry in Jack's mouth and the grand, long-term tattoo scheme Sissy has embarked upon.
We don't understand why such beautiful young people would want to mutilate their bodies... but it is clear to us that these are genuinely good, caring kids with their hearts absolutely in the right place, and that trumps all.
So my point is... your daughter's piercings and such seem tasteless and inexplicable to me, too -- but for some reason you and I can't grasp, these things are evidently very meaningful to kids now, a vital part of their identity (in their minds).
It's so much more important that your daughter be with you for Christmas than that she look any particular way...isn't it? And by being the bigger person, by calling her and saying "All right, sweetheart, come as you are, just come," you can set a GREAT example of what it means to love unconditionally.
That's what I'd do, if I were lucky enough to be a mom.