Trying to shut it down is probably going to create more interest, Streisand effect type thing. I would leave it to burn out on it's own. It sounds like a net positive on the whole.
Hard to tell if there is really a problem here. "a number of female students" reached out to her with concerns, but "a few fellow profs either find it comical, or are happy that open labs are so full of volunteer tutors" and the boys are leading labs and offering tutoring.
Of course there are hidden motives, but it sounds like for the most part everyone is getting something useful out of this.