That's a tough one.....especially since she is so young.
My son who is now 27 months has in the past pulled my hair, and the odd time has hit my husband and myself and even rarer has bit me when he was in a "wild" mood.
I would always react in a way to show him that it hurt by saying "Ouch, that really hurt mommy". He would just look sort of surprised. I would also ask him to say "sorry" and kiss my "boo boo" better.
Another thought/idea would be the next time she does it and you tell her no, tell her that you won't be able to play with her from now on unless she "plays nicely" and go on to explain as best you can what that means.
If she's getting a little out of control just walk away until she calms down and then go over and give her a big hug. Eventually, she will get the idea.....hopefully
Good luck and happy holidays.