RAI- The holidays stink. There's no real way around it.
I know it's hard to keep your cool in these situations, but you can tell her that what she is doing is destructive all you want, but she will have to realize that on her own. In fact, I suspect that hearing it from us just makes them dig in their heels sometimes and determine to prove us wrong.
I would suggest that the next time a holiday comes up - that it not be all her decision (although you may have a mediation plan in place before that).
Hang in there - sorry about your work schedule. While not a physician, I am a healthcare analyst - and there are several CMS programs that have a deadline today, so the entire month has been crazy- I can somewhat relate - although obviously, I do not have lives in my hands. Take care of yourself.