I used that technique as a ball-parking to get me close, and then fine tuned from there. It worked that time, but given the range of differences in gender physiques it wouldn't surprise me if it were less successful overall with women.
Women in general are mysterious, sometimes confusing, and often misunderstood beings, that we, as simple minded men, may never fully understand. Still, the journey to understanding must go on, it is in human nature to seek understanding!! Ha ha
In reality, that is what I started off trying, I was trying to "teach" my wife about fitting a rifle, and showed her how, when putting the butt of the stock in the crook of my elbow, my trigger finger reached perfectly on my standard LOP Manners EH-1. Then I had her try to show her why this stock didn't fit her.....and low and behold, her finger placement was nearly identical to mine, even though she is 7" shorter than me. There was a moment of silence as I observed, a slight amount of confusion, and a very small amount of regret when I realized I would have to admit to my wife I did not expect that, nor had I seen it before ha ha, the "all knowing" husband didn't know! Ha ha
She did agree though, that a "standard" LOP is simply too long, especially in some compromising field positions, she couldn't get behind the rifle properly. I had her get behind some other guns with 12.75, 12.5, and 11.75" LOP, and we decided 12.5 was perfect for her.