Jillian, I've been married and divorced. I learned the hard way about about "direct communication"! Don't F around with her! If u want to know why she said that rite then, ASK HER! And, TELL HER u didn't like it! That's probably all u need to do to clear the air and avoid a repetition.
However, if she laffs it off, explain clearly and calmly what will happen if she does it again. You'll turn the question around and ask HER why she STOPPED SHAVING HER ----, (add whatever u feel is appropriate), in front of the visitors! That should certainly end her snide comments!