1. Regardless of the state of the field, you haven't made an argument that these isn't her experiences.
2. Whatever the reason, the number of women involved in computing has been on the decline for the last twenty years.
3. The number of women in senior positions today might not reflect the number who enter the field twenty years if there was significant job discrimination or if women happened to have different preferences. The gender distribution of principals doesn't necessarily reflect the gender distribution of teachers.
I'm in no way doubting that the explanation offered is a possible one. I just don't think it's been seriously supported. Anecdotally, girls these days actually seem more interested in computers than when I was growing up, and I think that the high availability of computers is actually helping the situation, not hurting.
As for point number 3, you are of course correct in theory, but the reality is, there were already no girls in the middle school computer clubs of 1992, the high school programming classes of 1996, and the CS 101 classes of 1999. So I'm not really buying the idea that anything on the job is primarily responsible for the lack of women graduating CS in 2004 or becoming senior engineers in 2012.
Rule one of conversion optimization is to figure out where you're actually losing people in the conversion funnel. In tech, we're losing women while they're still girls, for whatever reason, and that's what we really need to track down and fix. Focusing on points after they've already left is premature, since if we can get more women coming through those steps in the first place, the dynamic will change anyways.
2. Whatever the reason, the number of women involved in computing has been on the decline for the last twenty years.
3. The number of women in senior positions today might not reflect the number who enter the field twenty years if there was significant job discrimination or if women happened to have different preferences. The gender distribution of principals doesn't necessarily reflect the gender distribution of teachers.