According to Bart Ehrman in Misquoting Jesus, that's an error, inserted to fulfill an ideological religious agenda. If you look at Paul's letters, it is clear that at least some of the early Christian groups were led or co-led by women.
I once receied a free CD in the mail trying to get me to sign-up for Famous College Courses or something like that. The Free CD I got was a lecture by Bart Ehrmann. I detected two glaring errors in the first 5 minutes of listening to him. I chucked the CD and I chuckle at the idea his personal opinion about Scripture is normative or orthodox