My current female voice is at 170 Hz. (I just had it test last week and my old male was around 130.) If I concentrate on it, I can keep it around 195 Hz. (I'm working with a speech Pathologists with a small group for the next 6 weeks to improve mine.) I have pretty good resonance and that has worked well for me even at 170 Hz, no one has said that's a male voice in person or even on an intercom like in a drive through. However on the phone, it's 50/50. However if I concentrate and keep it at 195 Hz, even on the phone it's 100% female.
Here is a chart that shows the ranges (courtesy of NY Speech & Voice Lab):

The average female voice is at 220 Hz. If I can keep it at 195, then I'll be a happy camper. But there is so much more than just pitch. Resonance, expressiveness, articulation, etc are extremely important.