פירוש על עבודה זרה 53:14

The problem with saying that a woman cannot circumcise is that Zipporah circumcises her and Moses’s son on their way back to Egypt. The Talmud tries to read this as if she told someone else to circumcise, or only began the circumcision. Needless to say, these are not the simple readings of the text.
In the Middle Ages there were occasionally women who performed circumcision, especially in remote areas with few men. Today, I do believe that in some circles it is possible to find mohalot, but the practice extremely rare and certainly not found in the Orthodox world.