For reasons that don't really bear examining I've been watching fairly randomly selected episodes of Enterprise (when I say randomly, I mean that I looked Memory Alpha's Vulcan Images Category, clicked on things that looked interesting, and made a list of episodes from all the series.) To my surprise, this sampling produced episodes of Enterprise that passed Bechdel.
Even though for almost all of this arc, the two women regulars were separated (Hoshi on the ship, T'Pol on Vulcan), T'Pol got to talk to both her mother T'Les and T'Pau about logic, philosophy, mind melds, disease, politics, the history and destiny of Vulcan. Sure, part of the time they were talking about Surak and Archer, but Archer spent so much time passed out from Surak that T'Pol was left with T'Les and T'Pau for conversational partners consistently often.
Heck, they even killed off T'Les and T'Pol and T'Pau kept passing Bechdel for another five minutes on their own before plot separated them.