I've been following up my analysis of self-recordings by using WASP to take a look at samples from some of my voice role models: Meryl Streep, Jody Foster, Mary-Louise Parker and Emma Thompson, for starters.
One thing I've noticed is that while those wider gaps in overtones are present for them as well, in many cases their range (fundamental frequency, as charted by WASP) actually drops quite a bit lower than mine did in some spots...as low as 120-150Hz in some cases, and often not going as high as I've been tending to. The average range is often not much higher than 200Hz. In
one recording of Emma Thompson, in fact, she starts around 180 Hz or lower and drops as low as 100 Hz.
Chart:

(Because there's also added music in the background of this example, the spectrogram is a lot "noisier" than it was with my samples, but you can still see the telltale bands that match the spoken words... wish I had an easier way to find just the voice recordings for these... and I expect i will find some in due course. But the point of this exercise is really to confirm for myself that analysis of frequency will only go so far, and much of it is going in a useless direction when it comes to vocal training... though taking some samples to mimic and compare is in itself probably not a bad idea. I tend to think, though, that working on modifying my voice to remove the "male" clues and cues is going to be a somewhat advanced exercise. This is giving me some ideas of how to approach the challenge, and how to listen to and for those differences.
So much of getting this right has to do with finding ways to avoid activating those lower vibrations that are usually described as "chest voice" but which you can usually tell you are doing by placing fingers lightly on the voice box and watching out for the perceptible vibration that is common when speaking in a more "male sounding" voice.