Nazir 57: Men and Women Rounding One's Head, Shaving the Corners of One's Beard

We begin Perek VIII with a new Mishna about uncertain impurity.  If someone sees two nazirites together and one of them has become impure but the witness is not sure which one, both must shave and together they must bring an offering.

The Gemara wonders where this requirement comes from.  It seems that Masechet Sota teaches us that a private uncertainty results in impurity and a public uncertainty results in purity.  This makes sense in the context of Sota, where a woman has been accused of adultery.  If she was secluded with a man who was not her husband, a question about her status results in the conclusion that she is now impure.  

The Gemara also wonders how this requirement can be met at all.  To shave one's head in an uncertain case directly contradicts the prohibition against shaving the corners of one's head other than for the certain requirements of a nazirite.  

The Gemara suggests that the nazirites in question might have been women, for they are exempt from the commandment to leave the corners of one's hair uncut.  The rabbis also teach us that minor boys are exempt from this mitzvah.  In fact, the commandment states that men are forbidden from cutting the corners of their heads, or shaving the corners of their beards.  This cannot be referring to women, and thus the rabbis argue about whether or not women are actually permitted to cut the corners of men's hair.

It is always interesting to note when the rabbis decide that women are included in our mitzvot and when women are understood to be excluded.  As an aside, I wonder what the halacha should be for women who have beards.  Are we excluded because we are women, or included because we have beards?  And even if we are excluded, how many hairs are woman permitted to remove from our cheeks and chins?